After discovering an uncharted island, its isolated inhabitants are reintegrated into society. But, as time goes by, it's revealed that the island was actually Onigashima – the secret dwelling of numerous supernatural beings visited by the legendary hero Momotaro. Seeking revenge against Momotaro's descendants, a few of these demons set their sights on middle-schooler Momomoto Akira. Though she's initially reluctant, Akira befriends one of the island's transfer students, only to find herself in the crosshairs of other vengeful demons.
