A quiet, plain-looking female college student wearing glasses has just moved to the city for university. She appears to have no boyfriend, yet every night strange moaning sounds can be heard from her room—it's the sound of her enjoying solo pleasure. As the building's caretaker living right next door, he gradually gets involved with her and freely indulges in her voluptuous K-cup body. Despite her modest appearance, she has an unexpectedly horny nature, possessing more than enough allure to be trained and dominated. Once he discovers her secret, the caretaker can't bring himself to let her go.