In a Japan that differs slightly from our own, the youkai, supernatural beings, have begun coexisting with humans. In a regular school, students of all kinds of monsters attend their classes. Human boy Oohashi Shingo becomes attracted to one such creature, a petopeto named Fujimura Hatoko. Hatoko, affectionately called Petoko, is a minor monster whose only power is to stick to whatever she loves. Like Shingo…