As a result of a promise he made to his grandmother before her passing, Senguu Fumihiro sets out to find a suitable spouse for himself. He takes up admission at an esteemed institution with this objective in mind. However, his plans are disrupted on his very first day when a frenzy of violence breaks out among the students, with some even transforming into monsters. Luckily, he is rescued from imminent danger by a girl labeled "Akari," dispatched by one of the ruling factions of the school to safeguard him.
