Childhood friends Yuka and Hiroyasu are always competing with each other but one day they get into a fight over whether Yuka is "sexy" or "not". Yuka suggests they settle the score with an "erotic contest". Hiroyasu, irritated by her taunts, tried to punish Yuka, who refuses to back down from the challenge, with a naughty prank. But he found himself getting more and more aroused...