Set in 1963 in the fictional city of Kurashima, two rival yakuza factions collide as the Kawade family, led by Katsumi Kawade Mikio Narita, and the Ohara family, under acting boss Kenji Hirotani Hiroki Matsukata, bid for control. The Kawade faction is allied with ex-boss and city councilman Masaichi Tomoyasu Nobuo Kaneko, while the Ohara camp counts on ties within the local police. The balance of power and loyalty becomes the heartbeat of the city as raids, betrayals, and political pressure escalate.
An incident at a Tomoyasu bar triggers a brutal sequence: Ohara men raid one of Tomoyasu’s bars for a hostess who once worked for Hirotani, and the blame is pinned on a chosen Ohara member. Detective Kuno Bunta Sugawara obtains information on an illegal land auction deal involving the Kawade, Tomoyasu, and the local oil company Nikko Oil. Acting on this information, Hirotani leaks details of the deal. The land auction is put on hold, and Hirotani gains leverage by moving to control it. He offers to sell it back to Nikko Oil executive Kubo, but Kubo refuses. Elsewhere, Ohara members and their police allies clash with a truck driver revealed to be working for Kawade. This incident becomes a pretext for an all-out gang war against Hirotani.
With the war in full swing, Kawade, Tomoyasu, and Kubo meet with Police Commissioner Kikkuchi. Lieutenant Shoichi Kaida [Tatsuo Umemiya] is assigned to lead the crackdown against the Ohara family. Kaida orders the officers—Kuno among them—to stop fraternizing with the yakuza, and makes his point by smashing bottles of sake Hirotani had sent to the police one night. Yoshihura, one of the officers on Tomoyasu’s payroll, gets into a fight with Kaida, resigns, and joins Tomoyasu’s law office.
As the conflict intensifies, Boss Ohara is released from jail. Hirotani grows angrier as Kuno and his men are no longer tipped off about upcoming raids. After a raid at the Ohara headquarters, Boss Ohara is taken in for questioning and, following Tomoyasu’s advice, agrees to retire permanently, disband his family, and surrender his rackets to Boss Kawade. Kuno, meanwhile, lets one of Hirotani’s men go free; that man is arrested later, and he believes Kuno sold him out. A heated argument between Kuno and Kaida over the proper method to deal with the gangs unfolds. Kubo, preferring cooperation with the gangs, faces suspension after a confrontation with Kaida.
Desperate for revenge, Hirotani and his remaining men kidnap Yoshihura just as Hirotani’s arrest warrant arrives. The police mobilize to besiege the hotel, but every attempt to force a surrender fails. Kawamoto, a friend of Hirotani’s right-hand man Tsukahara, is killed after trying to intervene in negotiations. Kuno is recalled to defuse the situation, infiltrates the hotel, rescues Yoshihura, and subdues Hirotani after the hotel is tear-gassed. Kuno then arranges a deal with Kaida: the Kawade family will be disbanded, Hirotani and Tsukahara will receive light prison sentences, and Kaida will admit that Kuno was right about how to handle the gangs. If he refuses, Kaida will resign and risk exposing corrupt officers, including himself.
With the terms agreed, Hirotani’s men surrender and the violence subsides. An epilogue reveals that Kaida resigns from the force two years later and takes a position with Nikko Oil, while Kuno is transferred to another city as a patrolman. One night after his shift, Kuno encounters a pursuing truck that refuses to heed signals, and he is killed in a fatal pursuit, underscoring the perpetual cost of the city’s underworld battles.
