The "Guest House of the Moon" is not like any other hotel. A supernatural place, the hotel is not visible in its true form during the daytime as humans can only come across the hotel under special circumstances such as an invitation or lunar eclipse. Its staff and clients are all souls/ghosts coming to terms with unfinished business in their former lives before they pass on to the afterlife and cycle of reincarnation; the staff in particular have been there for decades and even centuries as they have not settled their grudges. The exception to this is the hotel general manager, which has been filled by a succession of human "passerbys" since they need to interact normally with the real world in instances like paying bills or fulfilling ghosts' requests with still-living relatives/friends. Some of the more powerful or long-lasting ghosts can make themselves present among humans but they have to abide by the guidelines of the deities Mago and Grim Reaper; for instance killing a human being will usually result in the soul being destroyed without going on to the afterlife. Ghosts can see other ghosts and humans, however only a select few humans such as the Guest House of the Moon manager can see ghosts.
Jang Man-wol (Lee Ji-eun) is the owner of this hotel, currently known as the "Hotel del Luna" that is located in Myeong-dong, Seoul. Due to a huge sin committed a millennium ago, the hotel catering to the dead has been bound to her soul. As a result of manipulation by the deity Mago (Yi-suk Seo), she meets Gu Chan-sung's father and makes a deal for his son to work for her after 20 years in return for his life and money. With his new found fortune and life, his father takes Gu Chan-sung(Yeo Jin-goo) abroad where the young man grows up as a sincere perfectionist who is level-headed, but also has a soft heart. He comes back to South Korea after his father's death to be an assistant manager at a multinational hotel corporation, only to face Jang Man-wol and he ends up fulfilling the agreement and becomes the manager of Hotel Del Luna.
Through Gu Chan-sung, the audience is introduced to the mysteries and the secrets behind the Hotel and its owner.
The beautiful but moody owner of Hotel del Luna (Guest House of the Moon) for 1300 years. Condemned to be the owner of the hotel to atone for killing many people. Her character gradually softens after she meets Gu Chan-sung. After the accidental death of her parents in the wilderness Man-wol was found unconscious by a merchant and his son. Later she was taken in by Yeon-woo's mother and raised along with him. After the death of Yeon-woo's mother, the pair remained close as siblings growing up and founded a clan of bandits which aligned with the rebellion. Reaching adult hood she was initially warm, smart and brave, but also sarcastic. After robbing princess Song-hwa who was travelling near the bandits lived in she met Go Chung Myung a soldier serving the king after the initial scuffle the pair fell in love. After spending time with Go-Chung Myung he taught her to write her name. But after Go Chung Myung betrayed Man-wol according to the request of Yeon-woo whom he told about the threat of princess Song-hwa to keep her alive. After the bandits along with Yeon-woo were hung to death in rage and hatred Man-wol killed Go-Chung Myung, Princess Song-Hwa on their wedding night killing many others along the way, she searched for the guest house of moon for the dead to atone for her sin. Once she found it she became cursed to run the guest house eternally until she changes her attitude. Alternating between being cold/aloof and bad-tempered, she held grudges as the centuries passed until she met Gu Chan-sung and changed for the better. She is known for her love of gaudy and garnish outfits (over 100 in the series), and frequently drinking champagne.
The new general manager of Hotel del Luna, succeeding the previous manager, Noh Joon-suk. He is a handsome HarvardMBA graduate, who is hired as an assistant manager at one of Korea's top hotels. However, due to a deal his father made with Jang Man-wol twenty years before, Chan-sung is forced to become the general manager for the Hotel del Luna and overcome his fears in coping with the unseen world of ghosts. Being stoic and rational puts him at odds with Man-wol, particularly curbing her spendthrift and extortionist tendencies. Once he settles in at Hotel del Luna his compassion emerges, with a customer focus tailored to each of the ghost clients, then eagerly learning Man-wol's backstory and protecting her from committing further sins.
The longest employee of the hotel and the Sky Bar's bartender. He lived during the Joseon dynasty as the scholar Kim Shi-ik, who committed suicide after being removed from his position for writing stories about the lives of commoners. He waited for 500 years to clear his name.
The housekeeper and room service provider with an extrovert personality. She also lived during the Joseon era as a nobleman's wife. When she gave birth to a girl instead of a boy, the family took her child away to starve the baby whereas her husband slept with another woman to have a baby boy, in order to carry on the family name. She was driven to insanity after her daughter's death and was killed later on by her husband's men. She vowed to see the family tree die out and wishes to take the last heir of the family with her to the afterlife.
The hotel receptionist. He is nice and polite but does not like his job. He was accidentally killed by his friend during the height of the Korean War, who assumes his identity, and cares very deeply for his younger sister waiting for 70 years to leave to the after life together. He starts dating Jung Soo-jung / Kim Yoo-na but ultimately had to break up with her because he left to the afterlife.
Kang Mi-na as spirit of Jung Soo-jung / Kim Yoo-na (residing inside Kim Yoo-na's body)
A rich and arrogant student, whose physical body ends up being inhabited by the spirit of Jung Soo-jung, a schoolmate whom Yoo-na bullied and murdered by pushing her off a bridge. Yoo-na's spirit is obliterated by her parents, and so Soo-jung decides to remain inside Yoo-na's body and assume her identity to be able to live. She is hired as an intern.
A royal guard captain during the Goguryeo era who fell in love with Man-wol. He was forced to marry Princess Song-hwa and to capture the rebels and kill them to rid the king of suspicions and protect his clan as well as to spare Man-wol from punishment. Just after his marriage to Song-hwa, he intentionally allowed himself be killed by Man-wol out of his unwavering love and guilt towards her. The first guest of the hotel, he too has been repaying his sins and stayed by Man-wol's side due to a promise he made.
The co-leader of the bandits with Man-wol, he acts as a surrogate brother to her. They raided Princess Song-hwa's caravan that was guarded by Go Chung-myung. He was captured and killed under the lead of Go Chung-myung, which led to Jang Man-wol developing a deep grudge against the latter. He is reincarnated as police detective Park Young-soo, who becomes Lee Mi-ra's boyfriend (reincarnation of Princess Song-hwa).
Chan-sung's best friend when they were studying at Harvard. He is the son of a wealthy pizza franchise operator, running the restaurant in Seoul. He opens up his house to Chan-sung and Lee Mi-ra. He eventually learns the truth about the Hotel del Luna after his girlfriend's death.
A princess during the Goguryeo era who was attracted to Chung-myung and later married him. She oversaw the destruction of Man-wol and Yeon-woo's clan of bandits, and during her wedding night was slain by Man-wol in revenge. She is reincarnated as Lee Mi-ra, a doctor and Chan-sung's squandering ex-girlfriend. She returns to Korea hoping to rekindle the romance with Chan-sung but later becomes Park Young-soo's girlfriend.
A rich guy who was Chan-sung and Sanchez's schoolmate in Harvard. He had defamed Sanchez but was thwarted by Chan-sung, which resulted in him being Sanchez and Chan-sung's nemesis. He later commits suicide after being outed for committing a heinous crime and becomes a vengeful spirit who aims to haunt Chan-sung and his acquaintances for revenge.
On June 24, 2020, Studio Dragon announced that it would co-produce an American remake of Hotel del Luna with Skydance. Alison Schapker will be in charge of developing and producing the series. She will be working with Miky Lee, Jinnie Choi and Hyun Park of Studio Dragon, and David Ellison, Dana Goldberg and Bill Bost of Skydance Television.