Tougen Anki is a dark fantasy action manga where a young boy named Shiki Ichinose discovers he is the descendant of a legendary, ruthless warrior. He lives in a world where a group of inherited warriors called the Momotaro clan violently oppresses the Oni, a race of mutant humans with unique powers. After a tragic event, Shiki is taken in by the Oni and decides to join their rebellion, using his own dangerous inherited abilities awakened by a powerful mochi-like drug. The story is a brutal battle for survival and revenge, featuring intense, fast-paced fights and a unique blend of Japanese folklore with modern, gritty elements. Readers enjoy it for its high-stakes action, dark atmosphere, and the compelling moral ambiguity of a protagonist fighting alongside supposed monsters against a corrupt, self-righteous system.