In the HiGH&LOW universe, the S.W.O.R.D. area is divided among five dominant gangs: Sannoh Rengokai (Hoodlum Squad), White Rascals, Oya Koukou (Oya High School), Rude Boys, and Daruma Ikka. This fragile balance is disrupted when external forces conspire to seize control.
Kohaku, the former leader of the disbanded Mugen gang, is devastated by the death of his close friend, Tatsuya. In his vulnerable state, he is approached by Lee, a member of the South Korean mafia group Chanson, which is collaborating with the local yakuza faction, the Kuryu Group, to dominate the S.W.O.R.D. area. Lee manipulates Kohaku into joining their cause, exploiting his grief and desire for purpose.
To execute their plan, Chanson and the Kuryu Group enlist the help of two formidable gangs: Doubt, led by the ruthless Ranmaru Hayashi, and the Mighty Warriors, led by ICE. These gangs launch coordinated attacks across the S.W.O.R.D. territories, causing widespread chaos and destruction. Notably, the Mighty Warriors set the Nameless Road ablaze, resulting in casualties among its residents.
In response to these assaults, the five S.W.O.R.D. gangs recognize the need to unite against the common threat. They form an alliance to confront Kohaku and his coalition. The climactic battle unfolds at the Container Yard, where the combined forces of S.W.O.R.D., along with the Amamiya Brothers, face off against Kohaku's 500-strong army. During the confrontation, Kohaku comes to a realization about the manipulation he has been subjected to and the true nature of his actions. This epiphany leads him to withdraw from the conflict. Ultimately, the S.W.O.R.D. alliance thwarts Lee's plan, restoring a semblance of peace to their territories.
This film delves into themes of grief, manipulation, and the power of unity in the face of overwhelming adversity, highlighting the complexities of gang alliances and rivalries within the HiGH&LOW universe.