Yui is preparing herself to attend her friend’s wedding, but she’s unable to fit in her dress which is too tight, she then starts a diet and training plan with her son’s assistance. During their training sessions, Yui’s plump body and big tits arouses her son, who loses his marbles and fucks her right in the living room. This unexpected happening left Yui shocked, but wanting for more. The next day, fully aware of the taboo implications, Yui tells her son that sex could count as part of the diet plan and invites him for more.
