Kazuki Aikawa has worked as a university lecturer for a half year. He teaches the subject of ethology. He is fascinated by the mystery of living creatures and has a tendency to focus only on that. He is not good at following rules or being punctual which causes him problems working at the university. Kazuki's class is uncommon. He gives assignment to his students which allows the students to express themselves. The students get confused though, because Kazuki tells them he does not know the answer. The students are struck by Kazuki's peculiar manner. This leads them to remember how their minds were during their childhood years.