Bad Boys J(2013)

Bad Boys J is a Japanese series set in Hiroshima, where rival gangs compete for dominance. High school student Tsukasa meets three friends—Yoji, Hisao, and Eiji—who draw him into the world of "Gokuraku Cho," a mid-tier gang caught between the powerful "Beast" and "Nights" organizations. After defeating Shun, the gang's leader, in a fight, Tsukasa unexpectedly becomes the eighth leader of Gokuraku Cho. The series follows his journey navigating gang politics, friendship, and loyalty as he takes on new responsibilities and confronts the challenges of leadership in a dangerous underworld.