Shota, who goes to the gym. But he doesn't care about exercising and is obsessed with the huge ass of his instructor, Yui-sensei! One day, Shota ends up staying over at Yui-sensei's house! Seizing the opportunity, he gets a boner and plays a prank aimed at Yui-sensei's plump ass! Personal training somehow turns into a blowjob with her big butt sticking out! In the bath, washing together somehow turns into standing doggy-style sex! At night, even his perverted classmate crashes in, leading to a night of triple● with shaking ass flesh! Solve both lack of exercise and sexual frustration with big-ass exercises!
