Mashiro Ichijo passes as a handsome, popular boy at school while hiding a body that is male above the waist and female below. An unfamiliar nurse leads Mashiro to an infirmary in the basement that nobody remembers being there, and enrols him in a class held after hours. Its students enter a shared dream in the shape of their true selves and fight one another for the single thing that ends the class: graduation. Pulled between classmate Sou Mizuhashi and the fragile Kureha Fujishima, Mashiro cannot keep the dream and the daylight apart.