Yosuke, who is staying with his brother, is in love with his brother's Aoi, despite feeling guilty. One day, Yosuke witnesses Aoi masturbating due to sexual frustration. "Please! Just once!" Yosuke kneels and begs for a physical relationship. "...Will you keep it a secret from that person?"Aoi must have had a lot of sexual desire built up, as she surprisingly accepts Yosuke's request, with the condition that it be "just dry sex". However, Yosuke had a secret medicine he had prepared for this day...