Sana Matsushita is in her second year as a teacher.She was her homeroom teacher for the first time, and she was busy preparing for class until late every day.When Sana was making materials in the unpopular library as usual, her janitor Sugiura called out to her with interest.Sana can't hide her wariness from Sugiura, who doesn't have a lot of good rumors about her.However, Sugiura shows up at Sana's library again...