After being told by his wife that he lacks exercise, Atsushi ends up asking his neighbor, Aki, to train him. Though known as a gym instructor, Aki secretly struggles with a sexless marriage. Using training as an excuse, she begins touching Atsushi's lower body. With a dominant S personality, she can't stop at just once or twice—she locks his cock in a chastity belt and takes control of his ejaculation. She repeatedly torments him through masturbation shows, face sitting, fleshlight torture, foot massages, and more. Unable to withstand the pleasure, Atsushi is subjected to constant torment for an entire week until he finally reaches his limit.