Genji Takiya, Shun Oguri, is a newly transferred high school senior who arrives at Suzuran All-Boys High School, a place infamous for its population of violent delinquents. During freshman orientation, the yakuza arrive seeking vengeance on third-year Tamao Serizawa, Takayuki Yamada for assaulting some members of their gang, and mistake Genji for their target, triggering a brutal brawl on the school field.
Meanwhile, Tamao visits his best friend Tokio Tatsukawa, Kenta Kiritani, who has just been discharged from the hospital. Upon returning to the school, Tamao witnesses Genji defeat the last of the yakuza. That night, Genji goes to his frequented nightclub and meets Ruka Aizawa, Meisa Kuroki.
Genji then visits his father, Hideo Takitani, Goro Kishitani, the yakuza boss. Genji proclaims his ambition to conquer Suzuran, a feat his father had once sought but failed to achieve, and wins a promise to be acknowledged as his successor should he succeed. The next day, Genji challenges Serizawa, but Tokio steps in, urging him to make a real impression by taking down Rindaman, the legendary fighter who controls the school’s chaos.
When Genji encounters Katagiri Ken, Kyosuke Yabe, a yakuza who previously had his gang arrested, Ken attacks in retaliation but is knocked down with a single punch. Humble, Ken joins Genji on a mission to understand Suzuran’s power dynamics, and they head to a club to discuss Genji’s plans. Following Ken’s advice, Genji forms a disciplined army called GPS—Genji Perfect Seiha. Anticipating trouble, Serizawa also begins recruiting his own factions.
Genji quickly draws in several strong fighters, including Tamura Chūta, Suzunosuke Tanaka, and Shun Izaki, Sousuke Takaoka, along with other recruits who can help him challenge Serizawa. Serizawa grows wary but holds back for the moment. One of his lieutenants, Yuji Tokaji, Kaname Endo, launches covert assaults on GPS, badly injuring Chuta and hospitalizing Izaki.
The tension between the two camps escalates, but Makise Takashi’s influence helps keep Genji in check for the moment. Later, Tokio and Serizawa cross paths at a nightclub, and Tokio suffers a cerebral aneurysm that requires surgery, a procedure with only about a 30% chance of success. Meanwhile, Tokaji approaches Bandō Hideto, leader of The Front of Armament, with a plan to kidnap Ruka and inflame the conflict further. Yazaki Jōji, the yakuza boss, Ken'ichi Endô orders Ken to kill Genji, ignoring how such an act could spark a full-scale war between the clans.
Ken struggles with the order, grows fond of Genji, and decides to warn Hideo about the plot. Genji receives a call from Ruka, who says she is being held by men with skulls on their jackets and that their captors mentioned Bandō. Suspecting Bandō’s faction, Genji rallies the GPS and heads to the biker gang’s headquarters.
A fierce confrontation unfolds, but Bandō’s faction reveals that they had removed their skull patches after aligning with Tokaji. Bandō explains that the skulls were a strategic move to reshape alliances. After locating Tokaji and rescuing Ruka, Genji decides it is finally time for war against Serizawa.
They schedule the fight for 5:00 p.m., at the same moment Tokio’s operation takes place, with Serizawa hoping to fight alongside Tokio. The battle begins, and the tide initially favors Serizawa, but Bandō’s faction arrives to join GPS, leveling the field. The fight rages on through the night until only Serizawa and Genji remain. Meanwhile, Ken is dragged to the harbor to be executed for disobedience, but Yazaki’s plan backfires when Ken is saved by a bulletproof coat Seo—sorry, the coat turns out to be bulletproof, and Ken escapes to begin a new life.
Days later, Genji again challenges Rindaman, who stands as the final barrier to ruling Suzuran. Rindaman, Motoki Fukami, speaks with quiet wisdom, insisting that Suzuran can never be truly conquered and that there will always be another challenger ready to rise and fight.
