Asami Shiino, a cold, quiet, yet considerate teacher, is popular for her beauty and large breasts, though somewhat naive. Concerned about Masaki, a student in her class, she finds herself in a compromising situation after an unexpected turn, masturbating him while maintaining a serious facade, justifying it as just a job. Despite being covered in his semen, her expression remains unchanged. Masaki, aroused, takes advantage of his naive teacher.