Following their victory against Kohaku and his forces at Container Street, the five gangs of the SWORD area—Sannoh Rengokai, White Rascals, Oya Kohkoh, Rude Boys, and Daruma Ikka—experience a brief period of peace. However, the Kuryu Group's plan to construct a casino in the SWORD district continues to threaten their territory.
Cobra, leader of Sannoh Rengokai, proposes an alliance among the SWORD gangs to combat this looming threat. While some gangs are hesitant, citing internal issues or differing priorities, the alliance faces further challenges with the return of Ranmaru Hayashi, leader of the rival gang Doubt. Ranmaru, known for his ruthlessness, recruits the Prison Gang upon his release, intensifying conflicts within the SWORD area.
Amidst these tensions, the Amamiya brothers, Masaki and Hiroto, possess a USB containing evidence of the Kuryu Group's corrupt dealings with politicians. They collaborate with Kohaku, a former leader of the Mugen gang, to expose the group's illicit activities. This move puts them in direct conflict with Genji Kuki, a formidable assassin sent by the Kuryu Group to eliminate threats to their plans.
As battles rage between the SWORD gangs, Doubt, the Prison Gang, and the Kuryu Group's enforcers, alliances shift, and loyalties are tested. The film culminates in a decisive confrontation that will determine the future of the SWORD area, with characters facing choices that will shape their destinies and the fate of their community.