"That girl, is she a monster or a human?" The story revolves around a girl named Shikimi, who was born with a Mononoke (supernatural creature) attached to her. The particular Mononoke that possesses her is a Satori, which grants her the ability to read human thoughts. However, this also causes her appearance to transform into something monstrous when her emotions become too intense, leading the villagers to treat her as an outcast, calling her a monster. Shikimi's peaceful life with her mother is shattered when a man-eating Mononoke takes everything from her. After a Purifier named Ogata avenges her mother, Shikimi leaves the village with him. Together, they head to Showa-era Tokyo, where Shikimi embarks on a journey to face supernatural incidents and discover the meaning of her existence — neither fully human nor Mononoke.