Koji Igarashi at the Game Developers Conference in 2007.
|Occupation||Video game designer|
Koji Igarashi (五十嵐 孝司 Igarashi Kōji?), also known simply by the nickname IGA, is a video game designer and former producer of the Castlevania video game series. He is best known as the assistant director of Castlevania: Symphony of the Night, his first major involvement in the Castlevania series (he was partially involved in Castlevania: Rondo of Blood and is listed under "Special Thanks" in the ending credits). He served as producer between Castlevania Chronicles and up until Castlevania: Harmony of Despair. He has been involved in other titles such as the Japan-only RPG Elder Gate and Nano Breaker and the dating sim Tokimeki Memorial.
After graduating from college, Igarashi sought employment in the video game industry. He interviewed at a company, but an argument with its Human Resources department prevented him securing a job. A mentor of Igarashi then suggested he work at Konami, where the mentor worked. Igarashi passed the application exam, but lacked the university credits to work full-time. He worked part-time at Konami for a year while he attended school. In 1990, Igarashi switched to a full-time capacity. His first project was a simulation game for the Educational Software department. The title, however, was never released. Igarashi's first game to be released was Detana! Twinbee. Igarashi informed his boss that he had no desire to work on a sequel to Tokimeki Memorial, and requested a departmental transfer. The strong sales of the game prompted his boss to agree, and Igarashi asked to join the Castlevania development team. He left Konami in 2014 to form his own studio. 
He is credited as IGA, except where noted.
- Detana!! TwinBee (PC-Engine) - Programmer
- Gradius II (PC-Engine Super CD-ROM²) - Programmer
- Tokimeki Memorial (PC-Engine Super CD-ROM²) - Scenario Writer (as K. IGA)
- Tokimeki Memorial: Forever with you (PlayStation, Sega Saturn) - Scenario Writer
- Castlevania: Symphony of the Night (PlayStation) - Assistant Director, Programmer, Scenario Writer (as Kouji IGA)
- Elder Gate (PlayStation) - Director, System Programmer
- Castlevania Chronicles (PlayStation) - Producer 
- Castlevania: Harmony of Dissonance (Game Boy Advance) - Producer, Scenario Writer
- Castlevania: Aria of Sorrow (Game Boy Advance) - Producer
- Castlevania: Lament of Innocence (PlayStation 2) - Producer, Scenario Writer
- Nano Breaker (PlayStation 2) - Producer
- Castlevania: Dawn of Sorrow (Nintendo DS) - Producer
- Castlevania: Curse of Darkness (PlayStation 2, Xbox) - Producer, Scenario Writer
- Castlevania: Portrait of Ruin (Nintendo DS) - Producer
- Castlevania: Order of Shadows (mobile phone) - Producer
- Castlevania: The Dracula X Chronicles (PlayStation Portable) - Producer
- Castlevania: Order of Ecclesia (Nintendo DS) - Producer
- Castlevania Judgment (Wii) - Producer
- Castlevania: The Adventure ReBirth (WiiWare) - Producer
- Castlevania: Harmony of Despair (Xbox Live Arcade) - Producer
- Otomedius Excellent (Xbox 360) - Producer
- Leedmees (Xbox 360 Kinect) - Producer
- Sheffield, Brandon (2005-08-15). "Whip Smart: Konami's Koji Igarashi On Mastering Castlevania". Gamasutra. Retrieved 2010-02-10.
- Szczepaniak, John. "Before They Were Famouos". Retro Gamer (Imagine Publishing) (35): 75.
- Yin-Poole, Wesley (17 March 2014). "Castlevania developer Koji Igarashi leaves Konami". Eurogamer. Gamer Network. Retrieved 17 March 2014.
- VGMuseum.com: Ending for Detana!! TwinBee. Retrieved on 16 July 2007.
- VGMuseum.com: Ending for Gradius II. Retrieved on 16 July 2007.
- Tokimeki Memorial credits. Retrieved on 16 July 2007.
- Mr. P's Castlevania Realm: Credit list. Retrieved on 18 May 2009.
- VGMuseum.com: Ending for Castlevania Chronicles. Retrieved on 28 March 2008.
- Igarashi, Koji. "Leedmees Facebook Page Comment". Retrieved 7 September 2011.