Tanaka, who took a job right after university (or it's practice) at a high school near his home, but things are complicated by the fact that Endo Aina, his student, is flirting with him. She is a bright and cheerful girl and the one he used to help with his homework when he was a part-time homeroom teacher when he was a student. To be alone with Tanacacci in the teachers' lounge, she takes it upon herself to organize a school trip, and once she's alone, she asks him - "Tanacacci, listen... are you a virgin?" A downpour caught classmates Itsuki and Hosokawa while they were cleaning up near the sports closet. And what to do if they were soaked to the skin, and Hosokawa was silent as usual, but surprisingly attractive and erotic in her white shirt shining through from the rain...