Strange things start happening to Shinichirou Asano, a second year student. A woman turns into a centipede, and he sees a girl is attacked by a monster. During all the chaos, he runs into Sakura Shimazu, who uses a bow as a weapon. She is the 37th head of the Shimazu family, tasked with ridding the world of monsters. Shinichirou and Sakuya end up fighting one of the monsters together, when Shinichirou accidentally releases one of the creatures that Sakuya captures and they cooperate to catch it.