Reiko Kobayakawa, a beautiful and stunningly attractive teacher, was always the object of admiration among her male students. One day, while riding the train home, she suddenly becomes the victim of a molester. Trembling in fear, she remains silent and helpless as a male student named Yoshino, coincidentally riding in the same car, witnesses the entire incident. Excited by the scene, Yoshino secretly takes photos and saves them as evidence. The next day, he shows the pictures to Reiko and begins gradually blackmailing her. As a result, their relationship spirals into something increasingly twisted and perverse.