Shouko Asada is an introverted and quiet student enduring severe sexual coercion from classmates. To escape this abuse, she partners with Hiroshi in a blackmail scheme against their new teacher, Machiko Natsukawa. Hiroshi obtains compromising material related to the teacher's underwear, forcing her participation in organized sexual activities with students. Shouko's involvement in the plot arises solely from her desperation to end the harassment she suffers.