Tsukichan, a cheerful and innocent schoolgirl, is seen jumping rope alone when a perverted older man joins her, leading to a series of playful and provocative interactions. Tsukichan innocently treats the man like a pretend horse, draws on his body, and becomes fascinated with fetish items like a flat chastity belt and a fake penis. She begins to playfully tease the man's genitals, causing him to become erect and desperately wish for release from the chastity device—but his attempts fail. Frustrated and lonely, he eventually resorts to masturbation. Note: No ejaculation. Highlights include horseplay, body writing, flat chastity belt, and genital teasing.