Chaoyang, whose hobby is muscle training, learns that his son's friend, Kentaro, is not exercising enough, and teaches him various things. The size of the crotch that she accidentally touched reminds her of the sexual desire that cannot be released by training alone. And Chaoyang, who lost her desire, played with his and seduced her. However, her body climaxed many times due to his unequaled pretense that did not end once or twice, and she continued to raise her voice in agony. - In an unequaled copulation with him that seems to be eternal, Chaoyang finally gives up ...