There are 108 mental illnesses, including jealousy and hatred. Unlike the body, these illnesses cannot be cured by ordinary doctors. But there was a doctor who could fix it. His name is Dokuta Ii, a transfer student in class 5 and 2 of Kuoka Elementary School. He is usually a natural, but he is good at seeing through the mental illnesses of those around him, and is Dr. Dokuta, who fights and treats the illnesses that nest in them. Shortly after he transfers to a new school, he begins to cure the illness that is nesting in the hearts of his classmates and their guardians, but along the way he also comes face to face with a mysterious man who claims to be from "that world."