Empire of Kids (1981)
Following a stint in reform school, Ryu (Shinsuke Shimada) returns to his home, the Minami area of Osaka, accompanied by his new friend Ko (Takeshi Masu). He's greeted by his friends, Chabo (Ryusuke Matsumoto) and Ken (Bang-ho Cho). They seek to forge their own path through a multitude of rival gang