Keiji Harada is the twin brother of Noboru and childhood friend of Cobra and Yamato, joining up with them to motorcycle club Mugen, after being invited by a friend named Tsukumo and a new friend in the form of Kohaku, after being expelled from school due to fighting bullies that insulted his friend, Lala. The three try to get things to work until they find out Keiji's twin brother joins Lemura family, a part of the yakuza gang Kuryu Group. A plan is devised once it all starts to come together, but over time, Keiji starts to fall for Shiba, a member of an all-female biker gang, Ichigo Milk. The two would get along quite well, but Shiba starts to fall for Keiji and would start to have a lot of wet dreams about him. How does he react?