Tsubaki's husband is sexually indifferent and ejaculates as soon as she gives him a blowjob. Dissatisfied, Tsubaki indulges in masturbation. One night, her stepfather comes home and peeks in on Tsubaki while she is bathing. The next morning, after her husband leaves for work, Tsubaki's desire to have sex with her stepfather turns into pleasure, and she gradually complies with him. A few days later, her stepfather and Tsubaki conspire to have intense sex together. This is the most impressive work of Tsubaki Kato, a slender and beautiful mature woman.