As one of Onizuka's (GTO) few long-time friends, Danma Ryuji has witnessed all the messes he has gotten into. However, the motorcycle shop owner and self-proclaimed fastest driver in the city is about to face serious trouble. A teenage girl named Ishikawa Mimon begins to take an interest in Ryuji, but despite her appearance, she is a dangerous individual who will place him in life-threatening situations. Although he has a beautiful girlfriend named Nagisa, Mimon is set to disrupt Ryuji's peaceful life.