Kōtarō IsakaKōtarō Isaka.

Kōtarō Isaka (伊坂 幸太郎, Isaka Kōtarō; born 25 May 1971) is a Japanese author of mystery fiction, best known for his Hitman novel/manga series, including Maoh: Juvenile Remix (2007 to 2009), the first of which, 3 Assassins (2004, Japanese; 2022, English), was adapted as a Japanese feature film, Grasshopper (2015), and the second of which, Maria Beetle (2010, Japanese; 2021, English), was adapted as an American feature film, Bullet Train (2022).