A 38-year-old office worker leads a perfectly orderly and serious life in a desolate, forgotten industrial town by day, but by night he is a different person entirely. Under the name Kirin, he participates in dangerous, illegal street races organized within the decaying city, where his true passion for motorcycles finds its only outlet. This double life forms the core of the story, which is framed as a high-speed, motorcycle-centric action drama.

The setting is a near-future Japan, specifically an unnamed, isolated island where unconventional and illegal rules prevail. The protagonist, who goes only by the name Kirin, rides a modified Kawasaki Mach III (500SS). He is a drifter who wanders into a rundown town called Heihen-cho and discovers he cannot leave. The only way to escape this closed-off community is to win the deadly, high-stakes races that are held as a form of trial. This parallel-world narrative serves as a reboot of the larger Kirin saga, featuring no connection to previous storylines.

The main character, Kirin, is a mature and weathered rider whose calm, almost detached demeanor hides a burning desire for speed. He is opposed and aided by a cast of hardened characters, including a corrupt policeman named Pickles who confiscates Kirin's beloved Mach, forcing him to retrieve it in damaged condition. A young drifter, nicknamed Negi, arrives on the island and his reckless actions gradually expose the dark secrets and power struggles simmering beneath the surface. The island is controlled by a web of conflicting factions, including the police, corrupt politicians, violent gangs, and morally grey figures like a scrapyard owner and a bartender.

The narrative arc follows Kirin as he attempts to recover his motorcycle and uncover the town's secret. The story progresses from retrieving the damaged Mach to confronting the powerful forces that control the island. To escape, he must participate in and survive life-threatening races against a variety of opponents, including a Porsche 911 Carrera GT3 and police-tuned Nissan GT-Rs. The series builds towards a climactic series of trials where winning is the only path to freedom, forcing Kirin to push both his machine and his spirit to their absolute limits.