The inexperienced introvert couple is surrounded by extroverted slutty gals and is developed more and more...! The fate of boyfriend Akiho and girlfriend Suzune, who have never had any sexual experience yet, changes drastically when they meet their childhood friend Sayu, who has become a full-fledged gal. The two have their first experience at the hands of the gals, and discover the crucible of pleasure. When Suzune sees her boyfriend being taken advantage of by the three gals, she makes up her mind and pushes Akiho down...!?