Cells at Work!

Cells at Work!
First tankōbon volume cover, featuring Red Blood Cell AE3803 and White Blood Cell U-1146
はたらく細胞 (Hataraku Saibō)
Genre	Biology Fantasy comedy
Manga
Written by	Akane Shimizu
Published by	Kodansha
English publisher	NA: Kodansha USA
Magazine	Monthly Shōnen Sirius
Demographic	Shōnen
Original run	January 26, 2015 – January 26, 2021
Volumes	6
Further information Manga Cells at Work!: Bacteria! Illustrated by Haruyuki Yoshida Published by Kodansha English publisher NA: Kodansha USA Magazine Nakayoshi Demographic Shōjo Original run April 3, 2017 – July 3, 2020 Volumes 7 Manga Cells NOT at Work! Illustrated by Moe Sugimoto Published by Kodansha English publisher NA: Kodansha USA Magazine Monthly Shōnen Sirius Demographic Shōnen Original run July 26, 2017 – November 26, 2021 Volumes 5 Anime television series Directed by Kenichi Suzuki (season 1) Hirofumi Ogura (season 2) Produced by Yuma Takahashi Written by Yūko Kakihara Kenichi Suzuki Music by Kenichiro Suehiro MAYUKO Studio David Production Licensed by AUS: Madman Entertainment BI: MVM Entertainment NA: Aniplex of America SA/SEA: Muse Communication Original network Tokyo MX, GYT, ytv, BS11, MBS, TV Aichi, HBC, RKB English network SEA: Animax Asia Original run July 8, 2018 – February 27, 2021 Episodes 21 + Special Light novel Written by Yui Tokiumi Illustrated by Akane Shimizu Published by Kodansha Demographic Male Published July 12, 2018 Manga Cells at Work and Friends! Written by Kanna Kurono Illustrated by Mio Izumi Published by Kodansha English publisher NA: Kodansha USA Magazine Bessatsu Friend Demographic Shōjo Original run January 12, 2019 – April 13, 2021 Volumes 6 Manga Cells at Work!: Platelets! Written by Yuuko Kakihara Illustrated by Yasu Published by Kodansha English publisher NA: Kodansha USA Magazine Monthly Shōnen Sirius Demographic Shōnen Original run May 25, 2019 – April 26, 2021 Volumes 4 Manga Cells at Work!: Baby! Illustrated by Yasuhiro Fukuda Published by Kodansha English publisher NA: Kodansha USA Magazine Morning Demographic Seinen Original run October 17, 2019 – October 7, 2021 Volumes 4 Manga Cells at Work!: Lady! Written by Shigemitsu Harada Illustrated by Akari Otokawa Published by Kodansha English publisher NA: Kodansha USA Magazine Monthly Morning Two Demographic Seinen Original run January 22, 2020 – September 26, 2022 Volumes 5 Anime film "Hataraku Saibō!!" Saikyō no Teki, Futatabi. Karada no Naka wa "Chō" Ōsawagi! Directed by Hirofumi Ogura Written by Yūko Kakihara Music by Kenichiro Suehiro MAYUKO Studio David Production Licensed by SA/SEA: Muse Communication Released September 5, 2020 (2020-09-05) Runtime 112 minutes Manga Cells at Work!: White Brigade Written by Tetsuji Kanie Published by Kodansha English publisher NA: Kodansha USA Magazine Monthly Shōnen Sirius Demographic Shōnen Original run October 26, 2020 – July 26, 2022 Volumes 4 Manga Cells at Work!: Neo Bacteria Written by Haruyuki Yoshida Published by Kodansha English publisher NA: Kodansha USA Magazine Nakayoshi Palcy Demographic Shōjo Original run February 2021 – present Volumes 1 Manga Cells at Work!: Illegal Written by Kae Hashimoto Published by Kodansha Magazine YanMaga Web Demographic Seinen Original run February 1, 2022 – July 18, 2023 Volumes 4 Manga Cells at Work!: Muscle Written by Yū Maeda Published by Kodansha Magazine Morning Two Demographic Seinen Original run February 16, 2023 – present Volumes 1 Manga Cells at Work!: Cat Written by Choco Aozora Illustrated by Meku Kaire Published by Kodansha Magazine Monthly Shōnen Sirius Demographic Shōnen Original run May 25, 2023 – present Manga Cells at Work!: Medicine Written by Koma Warita Illustrated by Ryō Kuji Published by Kodansha Magazine Monthly Shōnen Sirius Demographic Shōnen Original run May 25, 2023 – present Other Cells at Work! Code Black (2018–2021)

Cells at Work! (Japanese: はたらく細胞, Hepburn: Hataraku Saibō) is a Japanese manga series written and illustrated by Akane Shimizu. It features the anthropomorphized cells of a human body, with the two main protagonists being a red blood cell and a white blood cell she frequently encounters. It was serialized in Kodansha's shōnen manga magazine Monthly Shōnen Sirius from January 2015 to January 2021. It is licensed in North America by Kodansha USA. A spin-off manga series, Cells at Work! Code Black, was published from 2018 to 2021.

The series has been adapted into an anime television series by David Production, with two seasons broadcast from July 2018 to February 2021, totaling 21 episodes. A theatrical anime titled "Hataraku Saibō!!" Saikyō no Teki, Futatabi. Karada no Naka wa "Chō" Ōsawagi! premiered in September 2020.

Plot

The story takes place inside the human body, where trillions of anthropomorphic cells each do their job to keep the body healthy. The series largely focuses on two such cells; a rookie red blood cell, AE3803, who often gets lost during deliveries, and a relentless white blood cell, U-1146, who fights against any germs that invade the body.

Characters

Erythrocyte / Red Blood Cell (AE3803) (赤血球, Sekkekkyū)

Voiced by: Kana Hanazawa (Japanese); Cherami Leigh (English)

A red blood cell who has just started her job, delivering oxygen, carbon dioxide and different nutrients all over the body. She meets Neutrophil when he saves her from an attacking pneumococcus bacterium. She is clumsy and gets lost often, but is determined to perform to the best of her ability. It is later revealed that she had encountered Neutrophil when they were younger, after he saved her from a bacterium.

Neutrophil (好中球, Kōchūkyū) / White Blood Cell (U-1146) (白血球, Hakkekkyū)

Voiced by: Tomoaki Maeno (Japanese); Billy Kametz (English)

A type of white blood cell, whose job is to kill pathogens infecting the body. Despite his violent and ruthless occupation, he's quite soft-spoken and gentle. When he was still in school as a young cell, he saved AE3803 from a bacterium after she got lost in a training exercise.

Killer T Cell (キラーT細胞, Kirā Tī Saibō)

Voiced by: Daisuke Ono (Japanese); Robbie Daymond (English)

A type of white blood cell that recognizes and kills various foreign matter and unhealthy cells. He is aggressive, cocky and rowdy, brutally taking pleasure in slaughtering pathogens and unhealthy cells. He especially looks down on white blood cells forming relationships with non-white blood cells, like Neutrophil's close friendship with Red Blood Cell. He is the sergeant of the Killer T Cells and is a harsh teacher to his students, the Naive T Cells. He has negative relationships with Helper T Cell and NK Cell, the former being his superior in the Killer T Division. In his youth, he was considered to be weak like the rest of the young T Cells, being only able to survive and complete training through the help of Helper T Cell, which at least made him stronger.

Macrophage (マクロファージ, Makurofāji) / Monocyte (単球, Tankyū)

Voiced by: Kikuko Inoue (Japanese); Laura Post (English)

A type of white blood cell. She and her kind appear as lovely maids in big dresses, armed with a variety of large weapons to fight various invasive pathogens, and are often shown smiling cheerfully even in the middle of combat. While inside blood vessels, she and her kind take on the role of monocytes, and wear hazmat suits over their dresses.

Platelet (血小板, Kesshōban)

Voiced by: Maria Naganawa (Japanese); Xanthe Huynh (English)

A type of cell responsible for reconstructing the body after various injuries. They are depicted as children, due to their small cell size, and act as construction and repair crew within the body. One platelet who carries a whistle on her neck serves as their leader and she is most prominently featured in the show, while a secondary yet shy platelet known as "Backward Cap" because she wears her cap backwards, also appears in the story.

Helper T Cell (ヘルパーT細胞, Herupā Tī Saibō)

Voiced by: Takahiro Sakurai (Japanese); Ray Chase (English)

A type of T Cell that determines strategy and courses of action for dealing with foreign invaders. He is the main commander of the Killer T Division and has an intellectual and smooth disposition, putting him at big odds with the rough and tough Killer T Cell, despite having undergone T Cell training together with him.

Regulatory T Cell (制御性T細胞, Seigyosei Tī Saibō)

Voiced by: Saori Hayami (Japanese); Erica Mendez (English)

A type of T Cell that mediates and regulates the correct function and magnitude of immunological responses. She usually acts as Helper T Cell's secretary, though she is capable of fighting when necessary. She went through T Cell training alongside Killer T Cell and Helper T Cell.

Naive T Cell (ナイーブT細胞, Naību T Saibō)

Voiced by: Mutsumi Tamura (Japanese); Laura Stahl (English)

A rookie T Cell who is too frightened to fight invasive microorganisms, until Dendritic Cell helps him transform into Effector T Cell. He and his kind are the students of Killer T Cell, from whom they receive harsh treatment and austere training.

Effector T Cell (エフェクターT細胞, Efekutā T Saibō)

Voiced by: Kenji Nomura (Japanese); Chris Tergliaferra (English)

A Naive T Cell transformed into a large, muscular and powerful T Cell.

Eosinophil (好酸球, Kōsankyū)

Voiced by: M.A.O (Japanese); Kayli Mills (English)

A type of white blood cell who is acquainted with White Blood Cell since they grew up in the same bone marrow. She feels inferior to the other immune cells because of her inability to fight off bacteria and viruses, but she shows her true worth by killing a parasitic Anisakis when the other cells could not. She handles a bident as her weapon of choice.

Dendritic Cell (樹状細胞, Jujō Saibō)

Voiced by: Nobuhiko Okamoto (Japanese); Griffin Burns (English)

Depicted as a messenger dressed in green stationed inside a call center resembling a tree. He can stimulate Naive T Cells and transform them into Effector T Cells. He owns a camera which he always uses to take pictures of events he deems important and stores them in picture albums, some of which are sources of shame and humiliation for the other cells.

Memory Cell (記憶細胞, Kioku Saibō)

Voiced by: Yuichi Nakamura (Japanese); Dave Vincent (English)

A paranoid and neurotic cell whose job is to remember past infections and allergies so that the immunity system can be ready for them. However, he is scatterbrained and it is difficult for him to sort out his memories, often panicking and screaming whenever disaster strikes.

Mast Cell (マスト細胞, Masuto Saibō)

Voiced by: Ayako Kawasumi (Japanese); Maureen Price (English)

A cell whose job is to monitor and release histamines in response to allergic and inflammatory reactions. She always follows the instructions in her book no matter the situations and is unpopular due to her lack of consideration of what her actions do to the other cells. Also known as "Fat Cell", she gets irked whenever she is referred to with that name.

Senior Red Blood Cell (AA5100) (先輩赤血球, Senpai Sekkekkyū)

Voiced by: Aya Endō (Japanese); Kira Buckland (English)

An older red blood cell who sometimes guides and teaches AE3803 on how to properly perform her occupation.

Junior Red Blood Cell (NT4201) (後輩赤血球, Kōhai Sekkekkyū)

Voiced by: Yui Ishikawa (Japanese); Jeannie Tirado (English)

A young but overly serious red blood cell who becomes AE3803's student.

B Cell (B細胞, Bī Saibō)

Voiced by: Shōya Chiba (Japanese); Erik Scott Kimerer (English)

A white blood cell who carries a weapon that shoots antibodies. He is often annoyed and jealous about not receiving as much credit as the Killer T Cells do. He also has an antagonistic relationship with Mast Cell, as their combined functions only cause grave disasters for the other cells.

Basophil (好塩基球, Kōenkikyū)

Voiced by: Tomokazu Sugita (Japanese); D. C. Douglas (English)

A mysterious and poetic character whose real occupation is unknown, appearing during a food-borne infection to make cryptic commentaries on the disastrous events unfolding.

NK Cell (NK細胞, NK Saibō)

Voiced by: Toa Yukinari (Japanese); Morgan Berry (English)

She patrols the whole body for viruses, bacteria and abnormal cells, with her weapon of choice being a machete. She has a smug demeanor, is somewhat condescending towards other cells and her relationship with Killer T Cell is akin to that of an intense sibling rivalry.

Cancer Cell (がん細胞, Gan Saibō)

Voiced by: Akira Ishida (Japanese); Khoi Dao (English)

An antagonistic cell bent on creating a world where cells no longer have to kill each other, even if it means risking the life of the body.

Normal Cell / Cell Boy (正常細胞, Seijō Saibō)

Voiced by: Yūsuke Kobayashi

Normal Cell is a minor character who plays a major role in season 2. Normal Cell is a soft-hearted troublemaker. He finds his job of copying himself boring hence he began to venture outside of his apartment to explore or mess around. Despite not being able to do anything, he has a strong will to protect someone that is precious to him (Lactic Acid Bacteria). According to AE3803, he lives by the pharynx, which happens to be an area that contains lymph nodes.

Media

Manga

Cells at Work! is written and illustrated by Akane Shimizu. It was serialized in Kodansha's shōnen manga magazine Monthly Shōnen Sirius from January 26, 2015, to January 26, 2021. Kodansha has collected the manga into five tankōbon volumes as of August 2017.

Kodansha USA announced that it had licensed Cells at Work! in North America on March 21, 2016. The manga is also licensed in Taiwan by Tong Li Publishing. Kodansha USA also announced that it has licensed Cells at Work! Code Black. Kodansha USA has also licensed five other spin-offs Cells at Work!: Bacteria!, Cells at Work!: Platelets! and Cells at Work!: Baby!, Cells at Work! Neo Bacteria, and Cells at Work! White Brigade.

Spin-offs

The manga received a spin-off in the May 2017 issue of Nakayoshi called Cells at Work!: Bacteria! (はたらく細菌; "Bacteria at Work") by Haruyuki Yoshida, which follows the lives of good and bad bacteria in the intestines. On June 3, 2020, it was announced that Cells at Work!: Bacteria! would end on July 3, 2020. A sequel series, titled Cells at Work! Neo Bacteria, began serialization on Nakayoshi and the Palcy manga app in February 2021.

Another spin-off, titled Cells NOT at Work! (はたらかない細胞; "Cells That Don't Work") by Moe Sugimoto, about immature red blood cells (erythroblasts) that do not want to work, was launched in the September 2017 issue of Monthly Shōnen Sirius. It published its final chapter on November 26, 2021.

The manga received another spin-off titled Cells at Work! Code Black (はたらく細胞BLACK), set in a "black" environment of a human body suffering an unhealthy lifestyle, that runs in Weekly Morning since June 7, 2018. It is written by Shigemitsu Harada, with illustrations by Issei Hatsuyoshi and supervision by Shimizu.

The manga received another spin-off titled Cells at Work and Friends! (はたらく細胞フレンド; "Cells at Work! Friend"), which centers around a Killer T Cell who is normally strict with himself and others, but wants to have fun during his free time. He also wants to make friends but does not want to ruin his reputation. The series began running in Bessatsu Friend on January 12, 2019. It is written by Kanna Kurono, and illustrated by Mio Izumi. It concluded on April 13, 2021.

Another spin-off series focusing on the platelet characters, titled Cells at Work!: Platelets! (はたらく血小板ちゃん, Platelets at Work) written by Kanna Kurono and illustrated by Mio Izumi, began serialization in the June issue of Monthly Shōnen Sirius that was released on May 25, 2019. It concluded on April 26, 2021.

Another spin-off series focusing cells inside the body of a baby 40 weeks since conception and nearing delivery, with the cells knowing nothing, titled Cells at Work!: Baby! (はたらく細胞ＢＡＢＹ) illustrated by Yasuhiro Fukuda, was launched in the 45th issue of Weekly Morning on October 17, 2019. It concluded on October 7, 2021.

Another spin-off series focusing on cells in the body of an adult woman, titled Cells at Work!: Lady! (はたらく細胞ＬＡＤＹ) written by Harada and illustrated by Akari Otokawa, was launched in the March issue of Monthly Morning Two on January 22, 2020. It concluded on September 26, 2022.

Another spin-off series focusing on white blood cells, titled Cells at Work!: White Brigade (はたらく細胞WHITE) illustrated by Tetsuji Kanie, was launched in the December issue of Monthly Shōnen Sirius, which was released in October 2020. The series ended serialization on July 26, 2022.

Another spin-off series focusing on the cells of a person taking illegal substances, titled Cells at Work!: Illegal (はたらく細胞イリーガル) written and illustrated by Kae Hashimoto, began serialization in Kodansha's YanMaga Web digital manga platform on February 1, 2022. The series ended with the serialization on July 18, 2023.

Another spin-off series focusing on muscles in the human body, titled Cells at Work! Muscle (はたらく細胞マッスル) written and illustrated by Yū Maeda began serialization on the Morning Two manga website on February 16, 2023.

Two spin-off series began serialization in the Monthly Shōnen Sirius magazine on May 25, 2023. The first spin-off is centered around cells in the body of a cat, titled Cells at Work!: Cat (はたらく細胞 猫), and is written by Choco Aozora and illustrated by Meku Kaire. The second spin-off is centered around medicine, titled Cells at Work!: Medicine (はたらく細胞 おくすり), and is written by Koma Warita and illustrated by Ryō Kuji.

Volume list

Cells at Work!

No.	Original release date	Original ISBN	North America release date	North America ISBN
1	July 9, 2015	978-4-06-376560-1	November 1, 2016	978-1-63236-356-5
1. "Pneumococcus" (肺炎球菌, Haienkyūkin) 2. "Cedar Pollen Allergy" (スギ花粉アレルギー, Sugi Kafun Arerugī) 3. "Influenza" (インフルエンザ, Infuruenza) 4. "Scrape Wound" (すり傷, Surikizu)
2	November 20, 2015	978-4-06-376589-2	December 27, 2016	978-1-63236-357-2
5. "Food Poisoning" (食中毒, Shokuchūdoku) 6. "Heat Stress" (熱中症, Netchūshō) 7. "Erythroblasts and Myelocytes" (赤芽球と骨髄球, Sekigakyū to Kotsuzuikyū) 8. "Cancer Cells (Part I)" (がん細胞（前編）, Gan Saibō (Zenpen)) 9. "Cancer Cells (Part II)" (がん細胞（後編）, Gan Saibō (Kōhen))
3	June 9, 2016	978-4-06-390633-2	March 28, 2017	978-1-63236-390-9
10. "The Circulatory System" (血液循環, Ketsueki Junkan) 11. "The Common Cold" (風邪症候群, Kaze Shōkōgun) 12. "Thymocytes" (胸腺細胞, Kyōsen Saibō) 13. "Acquired Immunity" (獲得免疫, Kakutoku Men'eki) 14. "Acne" (ニキビ, Nikibi)
4	November 30, 2016	978-4-06-390664-6	May 2, 2017	978-1-63236-391-6
15. "Staphylococcus aureus" (黄色ブドウ球菌, Ōshoku Budō Kyūkin) 16. "Dengue Fever" (デング熱, Dengu Netsu) 17. "Hypovolemic Shock (Part I)" (出血性ショック（前編）, Shukketsusei Shokku (Zenpen)) 18. "Hypovolemic Shock (Part II)" (出血性ショック（後編）, Shukketsusei Shokku (Kōhen)) 19. "Peyer's Patch" (パイエル板, Paieru-ban)
5	August 9, 2017	978-4-06-390720-9	November 21, 2017	978-1-63236-426-5
20. "H. Pylori" (ピロリ菌, Pirorikin) 21. "Antigenic Shift" (抗原変異, Kōgen Hen'i) 22. "Cytokines" (サイトカイン, Saitokain) 23. "Harmful Bacteria" (悪玉菌, Akudamakin) 24. "Cancer Cell II (Part I)" (がん細胞２（前編）, Gan Saibō Tsū (Zenpen)) 25. "Cancer Cell II (Part II)" (がん細胞２（後編）, Gan Saibō Tsū (Kōhen))
6	February 9, 2021	978-4-06-522252-2	June 22, 2021	978-1-63236-427-2
26. "A Bump on the Head" (たんこぶ, Tankobu) 27. "Left Shift" (左方移動, Hidari ni Idō) 28. "IPS Cells" (ips細胞, Ips Saibō) Special- "Psoriasis" (乾癬, Kansen) 29. "Novel Coronavirus" (新型コロナウイルス, Shingata Koronauirusu)

Cells at Work!: Bacteria!

No.	Original release date	Original ISBN	English release date	English ISBN
1	February 9, 2018	978-4-06-510910-6	July 7, 2020	978-1-64659-557-0
"Come Forth, Stinky Farts! Antibacterial Turf War" "Edible Fiber Incoming! The Good Bacteria Strike Back!" "Between Encampments - a Micro Meeting!" "Constipation Consternation! The Bifidum Blues" "The Most Numerous Bacterium in the Intestines is Me, Bacteroides!" "Names aren't Everything! Cry of the E. Coli" "I'll Put Some Pep in your Step! Lactobacillus" "Skin Condition Crisis! Staphylococcus Epidermis vs. Staphylococcus Aureus" "I'll Live on your Skin★ Malassezia Fungus" "Dropping in★ along with Your Food! Natto Bacteria" "Intestinal Ruin?! Salmonella (First Half)"
2	July 9, 2018	978-4-06-512138-2	August 4, 2020	978-1-64659-619-5
"Intestinal Ruin?! Salmonella (Second Half)" "Let's Make Magnificent Cavities! Team Cavity Bacteria" "What're You Doing In the Intestines? Yogurt Bacteria" "The Pimple's Source: Acne! (Propionibacterium Acnes)" "Alone With meat... Hehehe ❤ Aspergillus Oryzae (Koji Mold)" "Th-That Stinks! What On Earth Is That Fluffy Bacterium?!" "It's In Your Mouth No Matter What?! Periodontal Disease Bacteria" "Th-Th-That Itches! Athlete's Foot Fungus"
3	October 9, 2018	978-4-06-513423-8	September 1, 2020	978-1-64659-685-0
"Bow Down Before Me. 0157" "Into the Intestines Together With Vegetables! Butyric-Acid Bacteria" "It Absorbs Fat?! Sake Lees!" "Why Do Bad Bacteria Exist...? The Agony of Staphylococcus Aureus" "I Have Bad Skin Even Though I'm On Top of Skin Care... The Cause Is the Gut?!" "Stop Holding Back On Going To the Bathroom!" "What Happens If You Don't Eat Meat...? Nutrients and the Gut" "Even Around the Eyes! Fierce Battle and the Sty"
4	February 8, 2019	978-4-06-514602-6	October 6, 2020	978-1-64659-748-2
"Ice Cream! Ice! Sherbet! What Would Your Intestines Be Like Then?!" "Manicure Time♪ But Under Those Nails...? Pseudomonas Aeruginosa" "We're the Strongest❤ Team Miso!" "I've Gotta Do Something About This! Chapped Lips" "Together With You Ever Since You Were A Baby" "Your Mouth Stinks! What's the Cause?" "Green Tea's Secret Power Is What?!" "Extra: You'll Understand In Thirteen Pages! "Cells at Work: Bacteria!""
5	July 9, 2019	978-4-06-516434-1	November 3, 2020	978-1-64659-791-8
"The Angel's A Devil?! A Day In the Life of Bacteroides Bacteria" "A Must-See! The Correct Way of Washing Your Hands" "Popping Up On the Finger! Warts!" "If You Don't Drink Enough Water... Watch Out! The Intestines and Dehydration" "I Want To Improve! Mouth Discomfort When You Wake Up!" "Armpit Care Is Important! Armpit Odor Causing Bacteria" "Red Pimples! What Causes Them?" "Our Leader Is..."
6	December 9, 2019	978-4-06-518183-6	December 1, 2020	978-1-64659-853-3
"Little Longum and Mini Longum's Efforts!" "What Happens When the Skin Gets Sunburns?!" "The Dreadful Norovirus!" "Familiar Problems! The Fascinating Nail Troubles!" "This Place Is A Music Venue?! The Bad Bacteria's Rampage!" "The Dimwitted Bug!" "Keep Your Legs Beautiful! Your Skin-Care Routine Shouldn't Be All About the Face★" "The Lactobacilli Who Cheer On the Host" "More "Cells At Work: Bacteria!""
7	August 6, 2020	978-4-06-520572-3	January 5, 2021	978-1-64659-901-1
"Good Bacteria On the Double!" "It's Not Just Bacteria! The World of Viruses You Never Knew About" "The Intestinal Environment Says Everything About the Host's Life" "The Host's Tiny Slip-Up Stirs Up A Storm and Bacterial Proliferation!" "The Staphylocococcus Aureus bacteria Aim For A New World Record!" "The Melancholy of An Elite Streptococcus Pyogenes Bacteria!" "A Secret Paradise In the Body" "Bacteria At Work (Part One)" "Bacteria At Work (Part Two)"

Cells NOT at Work!

No.	Original release date	Original ISBN	English release date	English ISBN
1	July 9, 2018	978-4-06-511982-2	October 1, 2019	978-1-64659-012-4
1. "Erythroblasts in Moratorium" 2. "Cells Unable to Work?" 3. "Macrophage's Grand Scheme For Enucleation! ☆" 4. "Artists" 5. "871's Policy" 6. "328's Idol" 7. "What Even Is a Nucleus?" 8. "Speedy Erythroblasts" 9. "An Unacceptable Mascot" 10. "The Immoral Macrophage (Part One)"
2	February 8, 2019	978-4-06-514461-9	November 5, 2019	978-1-64659-097-1
11. "The Immortal Macrophage (Part Two)" 12. "Macrophage Chronicles" 13. "Cells with Insomnia" 14. "Ghost in the Cell" 15. "A Macro Oath" 16. "The Fable of King 3104" 17. "725" 18. "Enucleation Ceremony"
3	December 9, 2019	978-4-06-517763-1	August 18, 2020	978-1-64659-648-5
19. "A Red Boy with a Green Pet" 20. "Deep Crimson Takes the Stage" 21. "Reunion" 22. "Regarding My Little Sister Being Acquainted with the NEET I Excessively Fret About" 23. "036's Big Brother" 24. "Cells Still Not at Work" 25. "In a Certain Collection Pool" 26. "An Average Day in the Bone Marrow" 27. "The Defendant, 871"
4	January 8, 2021	978-4-06-520833-5	August 17, 2021	978-1-63699-300-3
28. "A Shut Door" 29. "An Afternoon in the Infirmary" 30. "Meg the Mega-karyocyte" 31. "Hide & Seek & Molecules" 32. "A Game of Shi-ritori" 33. "Cell-tural Exchange" 34. "Friends" 35. "Iron's Journey" 36. "The Duel (Part 1)" 37. "The Duel (Part 2)"
5	February 9, 2022	978-4-06-526711-0	July 26, 2022	978-1-68-491370-1
38. "All or Nothing!" 39. "Hero in White" 40. 1516's Strawberry Diary" 41. "Monster Teacher" 41.5. "Meanwhile in the Kidneys" 42. "Enucleation" 43. "Head Over Heels Dream Come True" 44. "What is a Nucleus? Part 2" 44.5. "Reminiscence" 45. "Red Blood Cell Nostalgia" Extra- "Phagocytosis Gourmet"

Cells at Work and Friends!

No.	Original release date	Original ISBN	English release date	English ISBN
1	June 7, 2019	978-4-06-515522-6	October 8, 2019	978-1-64659-065-0
"The Lone Wolf" "Hot Pot Party" "Ransomware" "Flower Viewing" "Rental Video" "Tree Climbing" "Mini Class Reunion" "Photgenic"
2	November 7, 2019	978-4-06-517636-8	March 10, 2020	978-1-64659-255-5
"Sleep Paralysis" "Ocean" "Summer Festival" "Motivation" "Tidying Up" "Recreation" "Zero Calories" "Relationship Rumors"
3	March 9, 2020	978-4-06-518909-2	August 11, 2020	978-1-64659-636-2
"After 7" "Autumn Doldrums" "Mountains" "Anger Management" "Year End Party" "Preparation" "New Year Sales" "Share Boss"
4	July 13, 2020	978-4-06-520155-8	November 10, 2020	978-1-64659-802-1
"Measles" "Chilly" "Mite" "Habit" "One Team" "Slump" "Boot Camp" "Girls-Only Party"
5	January 13, 2021	978-4-06-522041-2	August 10, 2021	978-1-63699-292-1
"Jogging" "Bonesetting" "Training Camp" "Cashless" "Clonal Selection" "Freestyle" "Latent Infection" "Loss of Appetite"
6	May 13, 2021	978-4-06-523220-0	December 14, 2021	978-1-63699-518-2
"A Present" "A Tour Around the Body" "Countdown" "Valentine" "Job Rotation" "P.R. Movie" "Staff Reassignment" "Killer T Cell"

Cells at Work!: Platelets!

No.	Original release date	Original ISBN	English release date	English ISBN
1	January 9, 2020	978-4-06-518185-0	July 14, 2020	978-1-64659-556-3
1. "The Little Work Group!" 2. "I Want To Be A Full-Fledged Platelet Soon!" 3. "Mini-Rangers, Move Out!" 4. "Tale of the Tumbling Coagulant Canister" 5. "Don't Call Me A Baby!" 6. "We've Been Invited!"
2	June 9, 2020	978-4-06-519798-1	October 27, 2020	978-1-64659-420-7
7. "Traveling 3,000 Leagues To Deliver A Letter" 8. "Being Myself" 9. "Break Time Under the Tree" 10. "The Platelets' Exciting 24 Hours!" 11. "For the Sake of What We Must Protect" 12. "A Thrilling Tour of the Small Intestine"
3	December 9, 2020	978-4-06-521697-2	July 20, 2021	978-1-63699-229-7
13. "Leader and Vice Leader At Odds" 14. "Tough Mud Balls" 15. "A Moment of Emptiness" 16. "The Way of the Adults" 17. "Anywhere But Here" 18. "Pool Duty"
4	June 9, 2021	978-4-06-521697-2	November 16, 2021	978-1-63699-468-0
19. "What I Want To Be" 20. "A Warm Place" 21. "Exciting Chekups" 22. "The Master Trainer's Secret" 23. "Will That Rare Card Come?" 24. "JJ Channel" Final- "Platelets at Work"

Cells at Work!: Baby!

No.	Original release date	Original ISBN	English release date	English ISBN
1	January 9, 2020	978-4-06-518231-4	July 21, 2020	978-1-64659-555-6
1. "Birth (Part One)" 2. "Birth (Part Two)" 3. "Pulmonary Circulation" 4. "Mother's Milk" 5. "Norovirus" 6. "Heat Rash" 7. "Immunity"
2	July 20, 2020	978-4-06-519640-3	November 24, 2020	978-1-64659-820-5
5. "Bump" 6. "Vaccination" 7. "F-Niichan" 8. "RS Virus (Part 1)" 9. "RS Virus (Part 2)" 10. "RS Virus (Part 3)" 11. "Feces" 12. "Choking"
3	February 22, 2021	978-4-06-522344-4	July 13, 2021	978-1-63699-227-3
16. "Pee" 17. "Diaper Rash" 18. "Growing" 19. "IgG" 20. "Teamwork" Bonus 1. "The Promise" Bonus 2. ""Niichan""
4	October 21, 2021	978-4-06-524975-8	May 31, 2022	978-1-64651-303-1
Bonus- "First Encounter" 21. "Food Allergies (Part 1)" 22. "Food Allergies (Part 2)" 23. "Selfish" 24. "Nowhere In This Body" 25. "I Hate Him" Final- "Senpai"

Cells at Work!: Lady!

No.	Original release date	Original ISBN	English release date	English ISBN
1	July 20, 2020	978-4-06-519908-4	September 12, 2023	979-8-88933-065-3
2	February 22, 2021	978-4-06-521937-9	October 10, 2023	979-8-88933-066-0
3	June 23, 2021	978-4-06-523599-7	—	—
4	May 23, 2022	978-4-06-528098-0	—	—
5	November 22, 2022	978-4-06-529758-2	—	—

Cells at Work!: White Brigade

No.	Original release date	Original ISBN	English release date	English ISBN
1	February 9, 2021	978-4-06-522323-9	November 9, 2021	978-1-63699-458-1
1. "An Admired Superior" 2. "First Training" 3. "Rival" 4. "Let's Phagocytize!" 5. "Lost Myelocyte" 6. "A Scratch" Special Bonus
2	September 9, 2021	978-4-06-524873-7	January 11, 2022	978-1-63699-558-8
7. "Teatime With Everyone" 8. "Enhance Your Image!" 9. "Field Trip in the Intestines" 10. "Physical Fitness Test With Everyone" 11. "A Bit of Rest and Relaxation" Special Bonus
3	March 9, 2022	978-4-06-527028-8	September 27, 2022	978-1-68491-498-2
12. "Portrait Battle" 13. "Heatstroke" 14. "Super-Secret (?) Training!" 15. "Pseudomonas Aeruginosa's Counterattack" 16. "White Blood Cell Observation Journal" 17. "Intern" Special Bonus Chapter
4	October 7, 2022	978-4-06-529454-3	March 28, 2023	978-1-68491-861-4
18. "The Backs of My Seniors" 19. "Two Band Cells" 20. "Training Camp Starts!: 21. "Test of Courage Rally" 22. "Sudden Debut?!" 23. "An Ordeal" Final- "Band Cell at Work" Special Bonus Chapter

Cells at Work!: Neo Bacteria!

No.	Original release date	Original ISBN	English release date	English ISBN
1	February 22, 2021	978-4-06-522665-0	November 2, 2021	978-1-63699-452-9
1. "The Gut Bacteria and the Host In Love" 2. "Staphylococcus Epidermidis Is the Ally of the Skin" 3. "Standing In Solidarity To Finish Off Viruses"

Cells at Work!: Illegal

No.	Japan release date	Japan ISBN
1	June 20, 2022	978-4-06-528141-3
2	November 18, 2022	978-4-06-529754-4
3	May 18, 2023	978-4-06-531694-8
4	September 20, 2023	978-4-06-533038-8

Cells at Work!: Muscle

No.	Japan release date	Japan ISBN
1	July 21, 2023	978-4-06-532422-6

Anime

An anime television series adaptation was announced in January 2018. It is directed by Kenichi Suzuki and animated by David Production, with scripts written by Suzuki and Yūko Kakihara, and character designs by Takahiko Yoshida. The series' music is composed by Kenichiro Suehiro and MAYUKO. The anime series premiered on July 8, 2018, on Tokyo MX and other channels. The series ran for 13 episodes. Aniplex of America licensed the series in North America and simulcast it on Crunchyroll. Madman Entertainment simulcasted Australia and New Zealand on AnimeLab, while Muse Communication licensed the series in Southeast Asia and South Asia, and simulcasted it on Animax Asia. MVM Entertainment acquired the series for distribution in the United Kingdom and Ireland. The opening theme is "Mission! Health Comes First" (ミッション！ 健・康・第・イチ, Mission! Ken - Kō - Dai - Ichi) by Red Blood Cell (Kana Hanazawa / Cherami Leigh), White Blood Cell (Tomoaki Maeno / Billy Kametz), Killer T Cell (Daisuke Ono / Robbie Daymond), and Macrophage (Kikuko Inoue / Laura Post), while the ending theme is "CheerS" by ClariS. A special episode premiered on December 27, 2018. Aniplex of America released the English dub on August 27, 2019.

On March 23, 2019, the official Twitter account announced that the series will receive a second season. The second season aired from January 9 to February 27, 2021. The main staff at David Production is returning for producing the second season, with the exception of director Kenichi Suzuki being replaced by director Hirofumi Ogura. The opening theme is "Go! Go! Saibō Festa!" by the main cast members, while the ending theme is "Fight!!" by ClariS.

A theatrical anime titled "Hataraku Saibō!!" Saikyō no Teki, Futatabi. Karada no Naka wa "Chō" Ōsawagi! was announced on July 4, 2020, as an advanced screening of episodes 4–8 later aired in the second season. Also shown with a short animation "Kesshouban: Eigakan e Iku". The main staff at David Production returned for producing the film, with the exception of director Kenichi Suzuki being replaced by director Hirofumi Ogura. It premiered on September 5, 2020.

Cells at Work

No.	Title	Directed by	Written by	Original air date
1	"Pneumococcus" Transliteration: "Haienkyūkin" (Japanese: 肺炎球菌)	Ken'ichi Suzuki	Yūko Kakihara	July 8, 2018 (2018-07-08)
Inside a human body, a red blood cell, named AE3803, is rescued from a sudden attack from a group of Pneumococcus bacteria by a white blood cell, named U-1146. Later, as AE3803 tries to find her way to the lungs to make the delivery, she discovers one of the bacteria has escaped and is planning an attack on the lungs, so she and U-1146 accompany each other to the lungs to pursue it. Upon reaching the lungs and parting ways with U-1146, AE3803 discovers Pneumococcus had been hiding in her package the entire time, waiting to target red blood cells for their nutrients. However, U-1146, who had caught onto the bacterium's plan, arrives in time and lures the bacterium into a trap, where he is ultimately sneezed out of the lungs.
2	"Scrape Wound" Transliteration: "Surikizu" (Japanese: すり傷)	Shigatsu Yoshikawa	Yūko Kakihara	July 15, 2018 (2018-07-15)
The red blood cells find themselves in trouble when the vessel they are traveling on is broken by a skin abrasion, with U-1146 and the other white blood cells forced to deal with all the germs that come through as a result. As the bacteria plot to eliminate all the neutrophils before backup can arrive, the white blood cells manage to defeat them while the platelets arrive to clot the wound, preventing more germs from getting inside. Afterwards, the platelets round up several blood cells and force them to be part of the clot, much to their chagrin.
3	"Influenza" Transliteration: "Infuruenza" (Japanese: インフルエンザ)	Yukihiko Asaki	Yūko Kakihara	July 22, 2018 (2018-07-22)
Naive T Cell is patrolling the body for influenza virus proliferation. But since he's never taken on the enemy before, he's completely terrified and useless. He finally ends up fleeing the battlefield, where the veteran Killer T Cells, Neutrophils and Macrophages are battling. Naive T Cell is filled with self-loathing until Dendritic Cell sees him and speaks to him kindly. This encouragement transforms him into Effector T Cell, a much braver and stronger form that joins the other immune cells in wiping out the influenza virus. However, a surviving virus mutates into Type A and proliferates again, so the fighting goes on.
4	"Food Poisoning" Transliteration: "Shokuchūdoku" (Japanese: 食中毒)	Satoru Kiyomaru	Yūko Kakihara	July 29, 2018 (2018-07-29)
A band of Vibrio bacteria invades the stomach. Basophil warns the immune cells about it, but confuses everyone by speaking cryptically. The immune cells defeat the invaders, but one of them, Eosinophil, was unable to land any good hits and had to be rescued. The other cells mock her as a weakling, except AE3803 and U-1146. The stomach then gets invaded by a massive Anisakis parasite. The immune cells are no match for it, but Eosinophil explains she is designed to battle parasites and kills it with a single stab. The other cells apologize for making fun of her and praise her as a heroine.
5	"Cedar Pollen Allergy" Transliteration: "Sugi Kafun Arerugī" (Japanese: スギ花粉アレルギー)	Satoshi Ōsedo	Yūko Kakihara	August 5, 2018 (2018-08-05)
The body inhales cedar pollen, which unleashes gigantic allergens. Though U-1146 points out the creatures are mindless and non-malicious, Memory Cell claims they bring impending doom. B Cell easily defeats the allergens, but Mast Cell releases a profuse amount of histamines within the body, which causes violent allergic reactions that damage the surroundings. Just as everyone blames Mast Cell for the destruction, the body takes a steroid to treat the allergy. The steroid appears in the form of a robot that indiscriminately destroys its surroundings until it loses power. The survivors realize all of this was caused by following Memory Cell's claims and trying to attack the allergens.
6	"Erythroblasts and Myelocytes" Transliteration: "Sekigakyū to Kotsuzuikyū" (Japanese: 赤芽球と骨髄球)	Takehiro Ueno	Yūko Kakihara	August 12, 2018 (2018-08-12)
AE3803 gets lost again and finds herself in her birthplace, the Red Bone Marrow. She reminisces on being a young Erythroblast being trained by a Macrophage on how to be a Red Blood Cell. One day, while practicing to evacuate from bacteria, she got lost and was separated from the others. She got captured by a Pseudomonas bacterium who intended to torture and kill her before moving on to other blood cells. A young Myelocyte came to her rescue, and although no match for the bacterium, bought enough time for Macrophage and a Neutrophil to arrive and kill the bacterium. She thanked the Myelocyte for helping her and they went their separate ways hoping to someday see each other again. In the present, she runs into U-1146. As he offers to guide her to her destination, she suspects the Myelocyte who saved her grew up to be U-1146. Later, U-1146 saves a Normal Cell from a Cancer Cell. The Normal Cell explains there are more Cancer Cells in his apartment complex. The Normal Cell leads U-1146, Killer T Cell, and NK Cell to his apartment, but Killer T Cell continually trades spats with NK Cell and stubbornly refuses to work with her. The group splits up and once they are alone, NK Cell reveals she knew the Normal Cell was actually a Cancer Cell in disguise.
7	"Cancer Cells" Transliteration: "Gan Saibō" (Japanese: がん細胞)	Shigatsu Yoshikawa	Ken'ichi Suzuki	August 19, 2018 (2018-08-19)
NK Cell battles the Cancer Cell, who is able to shapeshift and spread into the surrounding environment. Meanwhile, U-1146 and Killer T Cell run into Cancer Cell's multiplying clones. The Cancer Cells order massive quantities of nutrients to be delivered to the apartment to greedily sustain themselves, but AE3803 feels suspicious and alerts the rest of the immune system. The original Cancer Cell wants to destroy the body for designating him to die as soon as he was born. U-1146, Killer T Cell and NK Cell are cornered and about to be killed, until the other immune cells arrive. All the Cancer Cells are wiped out, with NK Cell delivering the final blow against the original one, but he vows revenge before dying in front of U-1146.
8	"Blood Circulation" Transliteration: "Ketsueki Junkan" (Japanese: 血液循環)	Sumito Sasaki	Yūko Kakihara	August 26, 2018 (2018-08-26)
AE3803 becomes tired of always getting lost and resolves to circulate the body without guidance. After a difficult journey, she manages to travel through the heart, then the lungs to exchange carbon dioxide with oxygen, then to the body's cells to exchange oxygen with carbon dioxide. U-1146 clandestinely followed her and helped return her dropped notes and hat, then killed some germs who tried to ambush her, all without her noticing his presence. U-1146 later tells Killer T Cell that he has gained an appreciation for all the hard work the Red Blood Cells do every day and hopes the immune cells can live in harmony with other cells, but Killer T Cell angrily punches him and orders him to get back to work. AE3803 meets U-1146 and tells him how her day went. Killer T Cell walks around seeing several immune cells mingling with other cells and irritably denies being envious.
9	"Thymocytes" Transliteration: "Kyōsen Saibō" (Japanese: 胸腺細胞)	Hitomi Ezoe	Yūko Kakihara	September 2, 2018 (2018-09-02)
As Killer T Cell and Helper T Cell get into an argument about the former's harsh training methods, Dendritic Cell shares his photo album with the Naive T Cells and explains the two's shared past. While training in the Thymus, the young Helper T Cell and Regulatory T Cell easily passed all the hand to hand combat and obstacle courses, but the young Killer T Cell struggled. The young Helper T Cell was disdainful of him for this, but eventually gave him advice that helped him pass the final test. Killer T Cell vowed to become a worthy defender of the body, while Helper T Cell decided to become a commander. In the present, Killer T Cell and Helper T Cell notice the photo album. Severely embarrassed, they both try unsuccessfully to take it from Dendritic Cell in order to burn it. Regulatory T Cell muses that they are both still morons as they were in training.
10	"Staphylococcus aureus" Transliteration: "Ōshoku Budō Kyūkin" (Japanese: 黄色ブドウ球菌)	Hironori Aoyagi & Yasufumi Soejima	Yūko Kakihara	September 9, 2018 (2018-09-09)
AE3803 is rescued from a germ by a mysterious immune cell called Monocyte, who doesn't speak and wears a hazmat suit. Later, the nasal cavity gets invaded by a band of Staphylococcus aureus. Vowing revenge for one of their number who was killed in "Scrape Wound", they combine their bodies into a powerful giant who is able to trap the white blood cells in a net of fibrin. A squad of Monocytes appears and sheds their hazmat suits to reveal that they are Macrophages; Monocytes being one of the many roles they play. The Macrophages easily defeat the invaders. As the white blood cells thank the Macrophages for saving everyone, AE3803 asks one of them how they fit their enormous dresses inside the hazmat suits, but she tells her it is a secret.
11	"Heat Stress" Transliteration: "Netchūshō" (Japanese: 熱中症)	Tarō Kubo	Yūko Kakihara	September 16, 2018 (2018-09-16)
The body suffers from heat stroke, leading to a heat wave inside and the supply of fluids being depleted. To make matters worse, a Bacillus cereus bacterium, who is not bothered by the heat, invades the body. While the other cells struggle to cope with the extreme heat, U-1146 pursues the bacterium, but grows fatigued. Just when it seems that all is lost, the body gets an injection of fluids, reviving everyone and allowing U-1146 to kill the bacterium.
11.5 (ONA)	"Heat Stress: If There Was Pocari Sweat" Transliteration: "Netchūshō: Moshimo Pokari Suetto ga Attara" (Japanese: 熱中症～もしもポカリスエットがあったら～)	N/A	N/A	July 8, 2019 (2019-07-08)
A commercial version of episode 11 in which the threat of heat stroke is averted thanks to the arrival of Pocari Sweat sports drink.
12	"Hemorrhagic Shock" Transliteration: "Shukketsusei Shokku" (Japanese: 出血性ショック)	Satoshi Ōsedo	Yūko Kakihara	September 23, 2018 (2018-09-23)
13		Ken'ichi Suzuki, Shigatsu Yoshikawa & Takehiro Ueno	Ken'ichi Suzuki	September 30, 2018 (2018-09-30)
Part 1: AE3803 is assigned to be a mentor to a new red blood cell named NT4201, but finds herself out of her depth. AE3803 is embarrassed when she gets them lost several times and finds that NT4201 seems to already know about the body, and that she prefers to do her job as efficiently as possible and not associate with non red blood cells. The body suffers a head injury which results in massive blood loss. NT4201 starts to panic due to the change in her perfect schedule, but AE3803 manages to get her back on track. As the body temperature begins to drop, U-1146 defeats germs that entered through the injury, then is horrified to realize the number of red blood cells have depleted. Part 2: The platelets struggle to seal the head wound, but increased blood pressure causes even more blood cells to be lost. With so few red blood cells, there are not enough to deliver oxygen to all the cells, and they start to die. The body temperature drops drastically, leading to a blizzard inside. NT4201 falls into despair, and rants that their actions are pointless and the body will die, but AE3803 refuses to give up. The body receives a blood transfusion. The new red blood cells, though confused by their new surroundings, agree to help deliver oxygen, saving the body. As the body's structures are rebuilt, NT4201 apologizes for looking down on AE3803. AE3803 and everybody else gets back to their normal routine.
Special	"The Common Cold" Transliteration: "Kaze Shōkōgun" (Japanese: 風邪症候群)	Yūki Morita	Akira Horiuchi	December 27, 2018 (2018-12-27)
A Normal Cell who is bored of his monotonous duties and annoyed by his rowdy Killer T Cell neighbors is befriended by a mysterious cell who doesn't speak and wears a strange hat. The two have fun pulling pranks on various cells. Eventually, the stranger reveals himself to be a cell infected by a virus, with his hat being the replicating virus. He attempts to infect the Normal Cell, but the immune cells arrive in time to wipe out the virus. After identifying the virus as Rhinovirus (The Common Cold), the immune cells lecture the Normal Cell to study so that he can identify pathogens in the future. Now appreciative of his neighbors, the Normal Cell invites the immune cells to a game of badminton.

Cells at Work!!

No. overall	No. in season	Title	Directed by	Written by	Original air date
14	1	"Bump" Transliteration: "Tankobu" (Japanese: たんこぶ)	Hirofumi Ogura	Yūko Kakihara	January 9, 2021 (2021-01-09)
While chasing a germ that thinks its cuteness will protect it, U-1146 meets Backward-Cap, a novice platelet who aims to become stronger. A sudden incident in the temple's area causes a breaking of capillaries, and the platelets must stop the internal hemorrhage, with some coaxing from Megakaryocyte (cell that produces platelets). Megakaryocyte at first berates them for being weak, then motivates them by offering medals. The platelets form human chains to reach across the injury and seal it with a clot.
15	2	"Acquired Immunity" Transliteration: "Kakutoku Men'eki" (Japanese: 獲得免疫)	Daisuke Chiba	Yūko Kakihara	January 16, 2021 (2021-01-16)
		"Peyer's Patch" Transliteration: "Paieru-ban" (Japanese: パイエル板)
"Acquired Immunity": Memory Cell receives visions of destruction and believes he has gained the power to see the future. The Parotid gland gets invaded by the Mumps virus. As the immune cells fight them, B Cell cannot create antibodies without Memory Cell's information, but Memory Cell is obsessed with trying to see the future again and is useless. When B Cell strikes him in frustration, he realizes he was actually seeing his memories of the past when the body received a Mumps vaccine. B Cell creates antibodies from the information and wipes out the virus. Afterwards, B Cell explains why it took him so long, resulting in the cells beating Memory Cell up. "Peyer's Patch": U-1146 takes AE3083 and NT4201 on a tour of the small intestine, but Killer T Cell berates him for not focusing on his job. The small intestine gets invaded by Campylobacter bacteria who take an Intestinal Epithelial Cell hostage. The white blood cells surrender and give in to the bacteria's demands to humiliate themselves. However, they were slowly luring the bacteria to a Peyer's patch where the bacteria are ambushed and destroyed. Afterwards, Killer T Cell apologizes to U-1146, but retracts his apology when U-1146 realizes he forgot about AE3083 and NT4201 and rushes over to check on them.
16	3	"Dengue Fever" Transliteration: "Dengu Netsu" (Japanese: デング熱)	Takehiro Ueno	Yūko Kakihara	January 23, 2021 (2021-01-23)
		"Acne" Transliteration: "Nikibi" (Japanese: ニキビ)
"Dengue Fever": The cells complain to Mast Cell when she releases excess histamines for a minor problem and causes inflammation, making her angry and vow not to do her job. The body gets bitten by a mosquito that sucks out several blood cells, then infects the body with the Dengue virus. The virus takes over Langerhans cells and they attack the body. Despite seeing the damage, Mast Cell refuses to release histamines until Basophil tells her to do what she thinks is right. The histamines distract the infected cells and alert the immune cells so they can wipe out the virus. The cells apologize to Mast Cell, but she gloats that she was right all along and did not do anything wrong with her previous histamine releases. "Acne": U-1146 investigates a pore that turned into a pimple and finds acne bacteria have enslaved the hair and sebum producing cells to keep them fed on sebum. The bacteria had also killed several Neutrophils and turned them into pus. A young hair cell almost gives in to despair and says they are only one hair and unimportant, but U-1146 tells him every individual is important. U-1146 fights the bacteria, but their king can regenerate indefinitely due to the sebum he consumes. Drawing on U-1146's words, the child encourages his brethren that they can help by producing an overload of sebum. The king gets so engorged that he can barely move, allowing U-1146 to kill him. U-1146 nearly drowns in the sebum, but survives.
17	4	"H. Pylori" Transliteration: "Pirorikin" (Japanese: ピロリ菌)	Hironori Aoyagi	Yūko Kakihara	January 30, 2021 (2021-01-30)
		"Antigenic Shift" Transliteration: "Kōgen Hen'i" (Japanese: 抗原変異)
"H. Pylori": Normal Cell, who dreams of saving someone like the immune cells do, finds four cute and tiny bacteria and keeps them as pets. AE3083 delivers oxygen to him while U-1146 detects the bacteria and confiscates them for future disposal just as he is called to the stomach. Normal Cell follows him, worried about the bacteria. The stomach is being attacked by H. Pylori. When Normal Cell saves the bacteria from falling debris, one of them beats up the H. Pylori, allowing U-1146 to kill it. U-1146 realizes that they are Lactic acid bacteria, benevolent to the body. The one that fought stays in the stomach while the others stay with Normal Cell. U-1146 thanks Normal Cell and invites him to join him on patrol. "Antigenic Shift": U-1146 and Normal Cell go to the small intestine, which is overloaded with Purine, but one of the lactic acid bacteria consumes it before deciding to stay there. Later, Normal Cell accidentally drops one of the remaining two into a storm drain. U-1146 sadly remarks that he has no authority over the immune response so he can't tell the other immune cells not to attack that bacterium if they mistake it for hostile, reducing Normal Cell to tears as he insults the immune cells for being heartless. Just then, NK Cell arrives.
18	5	"Cytokines" Transliteration: "Saitokain" (Japanese: サイトカイン)	Hitomi Ezoe	Yūko Kakihara	February 6, 2021 (2021-02-06)
NK Cell attacks Normal Cell for insulting the immune cells, but U-1146 defuses the situation. Dendritic Cell rescues the lactic acid bacterium that fell into the storm drain and cares for it. The small intestine gets attacked by influenza. The virus has mutated and are unaffected by the immune cells' attacks, causing NK Cell to collapse in despair. The lactic acid bacterium produces Polysaccharides that power up Dendritic Cell and help him produce Cytokines, portrayed as embarrassing photos that shock the immune cells and motivate them to become stronger and wipe out the virus. After bidding farewell to the bacterium, Normal Cell apologizes to U-1146 and gives him permission to take the last bacterium he has. NK Cell informs U-1146 that Cancer Cell has returned.
19	6	"Harmful Bacteria" Transliteration: "Akudamakin" (Japanese: 悪玉菌)	Takehiro Ueno	Yūko Kakihara	February 13, 2021 (2021-02-13)
U-1146, Normal Cell, and NK Cell go to the large intestine, which is full of toxic gas due to harmful bacteria. AE3083 joins the platelets on a tour of the large intestine. The main Killer T Cell has been promoted to a Memory T Cell and joins them in their search for Cancer Cell. U-1146 tells Normal Cell to go alone and find where the last lactic acid bacterium belongs. Harmful bacteria invade the large intestine, forcing Normal Cell to run while AE3083 helps the platelets evacuate. Cancer Cell ambushes U-1146, NK Cell, and Memory T Cell. They slay him, but it turns out to be a copy. The real one appears and beats them up, saying they will see which of them deserves to survive.
20	7	"Cancer Cell II" Transliteration: "Gan Saibō Tsū" (Japanese: がん細胞II)	Yasufumi Soejima & Hirofumi Ogura	Yūko Kakihara	February 20, 2021 (2021-02-20)
21	8		Yōhei Shindō		February 27, 2021 (2021-02-27)
Part 1: Normal Cell, AE3083, and the platelets continue to evacuate. Memory T Cell remembers Cancer Cell's techniques, giving his team the advantage, but they are shocked when Regulatory T Cell defends Cancer Cell, believing he is a Normal Cell that needs to be protected. U-1146 is injured and Cancer Cell traps him in a pod, saying he's fascinated with him for the contradiction of being a defender when his function is to kill. Cancer Cell strengthens himself by absorbing the carcinogens in the toxic gas and plans to kill the body so that everyone will be equal in death. Despite hearing this, Regulatory T Cell continues to defend him and effortlessly beats up NK Cell and Memory T Cell. Normal Cell is cornered by harmful bacteria. The lactic acid bacterium tries to defend him, but is swatted aside. Normal Cell orders it to run and it does. The bacteria start torturing him. Part 2: Normal Cell is rescued by the Neutrophils, but they start getting overwhelmed by the bacteria until the lactic acid bacterium returns with its brethren and they turn the tide. With the bacteria defeated, the toxic gas dissipates. Memory T Cell uses his ultimate technique, the T Cell Perforin Cannon Punch. Although it was a made up technique taught to him as a joke, it actually works, firing a beam from his fist that damages Cancer Cell enough that Regulatory T Cell finally recognizes him as an enemy and turns against him. Cancer Cell continues to fight, but without the carcinogens in the toxic gas, he weakens. U-1146 escapes the pod and slays him, with Cancer Cell calling him his friend as he dies. As the lactic acid bacteria repair the damage, U-1146 calls Normal Cell a hero for bringing them. Memory T Cell tries to teach the Naive T Cells the T Cell Perforin Cannon Punch, but cannot replicate what he did. AE3083 catches up with U-1146 before they return to their regular routine.

Light novel

A light novel adaptation of the manga titled as Shōsetsu Hataraku Saibō (小説　はたらく細胞) was published on July 12, 2018, by Kodansha. It is written by Yui Tokiumi and illustrated by Akane Shimizu and has three volumes.

Stage play

A stage play adaptation titled Tainai Katsugeki Hataraku Saibō (体内活劇「はたらく細胞」) was announced in the August issue of Kodansha's Monthly Shōnen Sirius magazine. The play was held at Tokyo's Theatre 1010 from November 16 to 25, 2018. The play which was directed by Tsuyoshi Kida, starred Masanari Wada as U-1146 and Kanon Nanaki as AE3803, while Keita Kawajiri wrote the script for the play. The last performance, which was held on the 25th, was also distributed live.

Mobile app

A tower-defense game for iOS and Android mobile devices titled Always Cells at Work (いつでも はたらく細胞, Itsudemo Hataraku Saibō) was announced in November 2018. The game service shut down on January 31, 2020.

Live-action film

A live-action film adaptation was announced by Kodansha and Flag Pictures on March 20, 2023. It will be directed by Hideki Takeuchi and the script of which will be written by Yuichi Tokunaga.

Reception

Rebecca Silverman of Anime News Network highlighted the educational aspect of the manga despite flaws in presentation of information, and ultimately found the manga entertaining with likable characters. Sean Gaffney of A Case Suitable for Treatment called it a "very fun shonen action manga", complimenting the manga's ridiculousness and humor. Ian Wolf of Anime UK News gave the British Blu-ray release of the anime a score of 9 out of 10, and described the show as the most bloody on television, because so many of the characters are blood cells and thus means it contains more blood than shows depicting much violence.

The 2016 Kono Manga ga Sugoi! guidebook listed the manga as the seventh top manga for male readers. Paul Gravett included the manga in his list of "Top 22 Comics, Graphic Novels & Manga" for October 2016. By July 2017, the manga had over 1.3 million copies in print; it had over 1.5 million copies in print by January 2018.

Dr. Satoru Otsuka, postdoctoral fellow in the molecular neuro-oncology department of Emory University School of Medicine in Atlanta, Georgia, praised the series' depiction of cancer cells during the series' seventh episode. Biology teachers at a high school affiliated with China's Southwest University were so impressed with the accuracy of the series that they assigned it as homework for their students.

See also

• Osmosis Jones, a 2001 American live-action/animated action comedy film and its spin-off television series, Ozzy & Drix, both of which feature a similar premise
• Once Upon a Time... Life, a 1987 French animated series with a similar premise

External links

• Official manga website (in Japanese)
• Official anime website (1st season) (in Japanese)
• Official anime website (2nd season) (in Japanese)
• Official anime site (in English)
• Cells at Work! (manga) at Anime News Network's encyclopedia