As a child, Usagi Mitsuki made a promise to a crying girl that when he grows up he will marry her. When he finally becomes an adult, she appears again to make good on his promise, but much to Usagi's surprise...

Kotarou Hayasaka is a new student at Oomiya High School, a prestigious boys school where the student council president is able to make a single school rule at the beginning of the year. This year, the student...