Sana Matsushita, second year as a teacher. I was in charge of my homeroom for the first time, and I was busy preparing for classes until late every day. Janitor Sugiura called out with interest when Sana was making materials in an unpopular library as usual. Sana can't hide her alertness in Sugiura, who doesn't have very good rumors. However, Sugiura appears in the library again for Sana ...