Starting high school plagued by a mysterious ailment, Hanae Ashiya's troubles escalate as a peculiar creature clings to him. Desperate for a cure, he turns to an exorcist and ends up indebted to the stern Haruitsuki Abeno. To repay his dues, Hanae must team up with Abeno to usher diverse youkai back to the Underworld, all while balancing this task with his school life.