Hikora, a young boy consumed by the search for his vanished sister Sorincha, enters Otokoyo—a ritualistic hide-and-seek game held in an abandoned city whispered to house vengeful demons. His unwavering goal is to rescue her, blending fierce determination with fragile hope rooted in their sibling bond.

Clad in the game’s mandated fox mask, his unique design faintly mirrors his inner resilience. He traverses the decaying urban labyrinth alongside fellow players, evading supernatural pursuers like Kimotori and Chitori, who methodically hunt children. As participants fall, Hikora emerges as the sole survivor.

The game’s climax exposes Sorincha as Oshira-sama, a nine-tailed fox spirit possessing her after her prior victory. This revelation cements Otokoyo’s cyclical curse: winners transform into demonic vessels. Hikora inherits Sorincha’s role as “it,” accepting a twisted demon mask that seals his fate. Now the Oni, he beckons new players into the ritual, perpetuating the city’s insidious cycle—harvesting youth to fuel its mechanical evolution.