Takemiya Union Tōjō-gumi Wakagashira Yasuda (Hitomi Matsuda) retaliates against the Kansai-based Myōjin-kai by attacking their office after an assassination attempt on Union chairman Shimamura (Shunsuke Kariya). Joined by Yamashina-gumi Wakagashira Kiryu (Yoshiyuki Yamaguchi), the two succeed and pledge to work as brothers without an official oath, dedicating themselves to their organizations and the Union. The Union faces upheaval with Shimamura's retirement announcement and the loss of his son, Katsuto (Hitoshi Ozawa). The leadership race narrows to Tōjō (Hiroyuki Watanabe), Yasuda's boss, and Yamashina (Masahiro Noguchi), Kiryu's boss. Just as Yasuda’s casino operation thrives, a police raid confiscates all earnings and forces its closure. In desperation, Yasuda turns to a certain man (Naoto Takenaka) for help.

A man suicides causing ruin for his family, reasons are unknown, but his son will decide to take revenge after a succesion of events.

Yasuda (Hitomi Matsuda), the Wakagashira of the Takemiya Union Tōjō-gumi, infiltrates the hideout of the Yamashina-gumi's Sakazaki (Junichi Kawamoto), who had been secretly engaged in organ trafficking. Yasuda tries to extract the truth from Sakazaki, but is killed by Detective Hyūga from the Organized Crime Division (Marubō). The blame is pinned on Yasuda, leading to his arrest. Two years later... In Yasuda's absence, the boss of the Tōjō-gumi, Tōjō (Hiroyuki Watanabe), is assassinated by a hitman from the Myōjin-kai. The situation changes drastically. Nikaidō (Tarō Kawano) pressures Yasuda to reestablish his oath of allegiance, but Yasuda firmly refuses. Frustrated by Yasuda's response, Nikaidō makes a certain proposal to the union's chairman, Shimamura (Shunsuke Kariya).

Kaisei Sakamoto is a 16 year old boy who is inclined to settle everything with his fists. He grew up in a town where you can see both Nagazaki and Gunkanjima, living with his father. His father, Genkai Sakamoto, runs a small ramen shop. The father-son duo has just recently had a large fight. The story showcases fragments of one's youth and the questions that crop up while growing up.