The story takes place at a high school, where they organize male and female students to participate in rural experiences. Ken and Yumi’s class is actually on a horse farm. When the girls attend horse riding and grooming classes, Ken uses an electric vibrator to attach them to the saddle, when the riding girlfriend vibrates and it stimulates the girls’ pussy. It makes them unable to control their libido. And at that time Ken was present to have sex with poor girls. What a naughty boy.