Maki lives with her son as her husband is away on a business trip. One day, her son brings his classmate Kuroi home... Maki feels a maternal love for Kuroi, who is lonely as a single parent, and embraces him tenderly. However, Kuroi, a bully, takes advantage of her kindness and pushes her down forcefully... Maki is troubled by the fact that she had a relationship with her son's classmate, and Kuroi continues to approach and play with her. Maki, who is at the mercy of the persistent young man's inexhaustible sexual desire, gradually becomes addicted to the sweet stimulation that resonates throughout her body...