Sam Yuk transfers to a school where Sueng Hyun and Wu Yeong are notorious for their prankster. On the day when they are supposed to have a bout, Sam Yuk brings along a flashlight and this creates the suspicion that Sam Yuk might be the one who steals from school. But when they find out that Sam Yuk is the son of the kind guard, they wipe off the dishonor of Sam Yuk. They unite to crack down on the school robbery.