Takiya Genji arrives at Suzuran and graffitis his name over Serizawa's graffiti Serizawa, King of Suzuran, turns it into Takiya Genji, King of Suzuran. During the freshman orientation lecture, Yakuza arrive at the school seeking third-year senior Serizawa Tamao to avenge an injury he caused to them. To show his worth, Genji fights and defeats the Yakuza, who mistake him for Tamao. Serizawa arrives, commically crashing Tokio Tatsukawa's bike after Genji brutally finish off the last of the yakuza thugs. The two briefly take in the looming threat of each other's presence before Tamao is arrested for not having a driver's license for a bike.
At that night, Genji meets Ruka in a nightclub, where she sings as an R&B singer. Genji declares his ambition of conquering Suzuran to his father, who failed in the task. They agree that if Genji conquers Suzuran, he may inherit his father's Yakuza family. The next day, Genji meets Serizawa and Tokio, who was a childhood friend of Genji's. Tokio manages to halt a potential fight in between the two and tells Genji to take down Rindaman before approaching Serizawa. Rindaman, who is giant-sized and a legendary figure in the school, ignores Genji, who instead finds Ken Katagiri, one of the Yakuza who Genji didn't fight. Ken attacks Genji for getting his gang arrested but Genji takes him down in one punch. Ken surrenders and takes Genji to a quiet bar to chat about Suzuran.
Ken, a former student at Suzuran under the Nakai faction, proposes teaching Genji about leadership and influencing others to join his army, in order to correct Genji's lack of strategy in his ambition. Genji follows Ken's advice that he writes in a small notebook and manages to easily conquer Chuta Tamura's class, admitting him into his army. Genji decides to acquire Takashi Makise by exploiting his weakness for sex. Ken arranges a group date, but due to Makise's obvious awkwardness around women, the date flops miserably. Makise joins Genji anyway, based solely on the friendship formed on the day.
Izaki Shun, a friend of Makise, proposes joining Genji, but ambushes him instead, to test his strength. Genji fights valiantly, and Izaki is impressed, despite thoroughly defeating Genji . He joins forces with Genji, forming the Genji's Perfect Seiha Army.
After Izaki was ambushed by Yuji Tokaji, Genji decides to take action. Genji, who was unused to caring for his fellow friends, claims that, "This really hurts". Later, Serizawa and Tokio meet Genji in a pub, but Tokio suffers a seizure and is rushed to a hospital, where he learns that he has a large cerebral aneurysm, and that the surgery required has a 30% success rate.
Angered by the provocations, Genji attacks Serizawa's classes even as Makise tries to stop him. Chuta is also ambushed by Tokaji, and as Genji tries to leave to attack Serizawa, Makise finally decides to leave the GPS Army, stating that he cannot follow a leader without control. Ken tries to encourage Genji, and learns that Genji 's father is Hideo Takiya, a former associate of Ken's.
Genji challenges Makise to a fight, with a condition that if Genji wins, Makise joins him again. Makise forgives Genji with their familiar, "Take all," gesture the two shared on the night they became friends. Genji holds back his tears of gratitude and playfully flips off Makise, the bond sealed again.
Izaki returns from the hospital and is given an awkward but warm welcome back by the Genji and his gang.
Ruka calls Genji, telling him that she is abducted and that her abductors wore jackets with skulls on the backs. Realizing that they are The Front of Armament, the GPS Army gathers and makes their advancement to the Narai Warehouse, The Front's headquarters. A fight ensues, and Hideto Bandou is impressed by Genji 's strength. He calls an end to fight to ask why Genji has chosen to oppose The Armoured Front. After Genji states that Ruka was abducted by men wearing jackets bearing skulls Bandou reveals that he has sealed the skulls and that none of his men bear the skulls on their backs. He then tells Genji that Tokaji might be behind the whole farce and tells him where he can find him. Finding Ruka there, Genji is finally bent for war against Serizawa.
Serizawa, who was not aware of Tokaji's actions, fights him and agrees to Genji 's proposal for an all-out battle on the school grounds. They decide to fight at 5 PM, at the same time when Tokio will enter operation, the idea being that Serizawa will fight alongside Tokio. The two share a cold stare down and leave. The next day, the two armies meet across the rain soaked school ground, Serizawa' army having 100 strong, GPS, 70. The two armies shout their battle cries and charge at each other.
The battle goes in Serizawa's favour, even though the GPS army fights strongly. Bandou and The Front of Armament joins the battle midway on the GPS' side, evening the odds. Towards the end, only Serizawa and Genji remain standing, and fight. The battle drags into the evening as Genji and Serizawa continue to pound on each other, both badly damaged and exhausted. Genji gains the upper hand and wins the fight against Serizawa, who receives a call informing him that Tokio's operation was a success.
Having defeated Serizawa, Genji finally meets Rindaman, stating that he has to be defeated if Genji is to be titled the king of Suzuran. Rindaman replies that Suzuran can never be conquered, as there is always someone left to defeat. Genji losses his fight to Rindaman.
After repeatedly losing to Rindaman, Makise suggests to Genji that they shouldn't worry about Rindaman for the time being and focus on taking the rest of Suzuran. However, Genji states that if he beats Rindaman, then they wont have to worry about taking the rest of Suzuran as they will follow him.
While walking on his way back home, Genji tries to buy a packet of cigarettes, but the machine is faulty. Narumi Taiga notices Genji struggling with the machine and helps him get the cigarettes. When Narumi can't find his lighter, Genji offers his to him. They don't know each others true identity or names.
The next day, Genji witnesses a group of Housen students and Serizawa's faction arguing and interupts. When a Housen student tell Genji he shouldn't be talking to Suzuran's head like that, refering to Serizawa as the head, Genji punches him out. This action broke the non-agression pact between Housen and Suzuran, and war is broken out between them.
Genji and Serizawa meet up at the request of Tokio Tatsukawa to form an alliance. Despite Genji beating Serizawa, Serizawa and his faction don't follow Genji as he believes that if The Front of Armament hadn't
up, then Serizawa would have won the battle. After the incident, the Mikami brother leave Serizawa's faction and join GPS.
After Suzuran get attacked by Housen and Suzuran is set on fire, Genji and his head followers go to Housen where Genji meets the head of Housen, Narumi Taiga. Genji recognises him as the person who offered to light his cigarette. They agree to fight at Housen. After agreeing on terms, Genji walks toward Narumi. The Housen followers quickly rush towards him thinking Genji will strike Narumi. but Genji places a cigarette in house mouth and lights it, returning the favour.
The next day, Genji tells his followers that it's over and that GPS is disbanded. While it looks like Genji was walking home, he was actually walking to Housen, to fight the entire school by himself. Izaki Shun notices this and tells Makise, ''You should know that Takiya Genji isn't that kind of man'' with Makise realising by saying '''Dont tell me'' and Izaki replying ''Get everyone ready, we're leaving as planned''.
Due to his action, Serizawa and his faction join GPS, with Serizawa saying to Narumi Taiga ''Did you really think we wouldn't follow our captain?'' aknowledging Genji as the leader. Suzuran fight their way into and Genji fighting at Suzuran shrine
Housen. Genji eventually reaches the rooftop to fight Narumi. He beats Narumi, witnessed byTamao Serizawa and Tatsuya Bitou, a freshman in Housen and the younger brother of Makio Bitou, Housen previous head. Serizawa offers his shoulder to lean on for the injured Genji and with the rest of Suzuran, walk back victorious.
On the final day of school before graduating, Genji fought Rindaman one last time, however, Genji would lose yet again. Sajima Yousuke (Suzuran's freshman war winner in Hana Tsukishima's senior year) secretly witnessed this fight when he was in his fourth year in grade school.