Kiseijuu, also known as Parasyte, is a Japanese manga series created by Hitoshi Iwaaki. It was serialized from 1988 to 1995 and follows the story of a high school student named Shinichi Izumi, who becomes partially infected by a parasitic alien. This alien, named Migi, takes over his right hand, leading to a unique coexistence where they must work together to survive against other parasites that threaten humanity. The series explores themes of identity, humanity, and the relationship between humans and nature. It has been adapted into an anime television series and live-action films, gaining popularity for its thought-provoking narrative and engaging characters. Kiseijuu raises questions about morality and what it means to be human in a world where survival often comes at a cost.