In the early 1970s, seventeen-year-old Shimada Eiji unites the bikers of Kanto and becomes the first leader of Specter, a notorious bosozoku gang. When he is sent off to reform school, command passes to his second-in-command, Kagami. Around the same time, Kanto's biker gangs enter their own Warring States period, and a rival to Specter rises in Kanagawa. Gangs strike alliances with their neighbors and then break them, and they even fight over who gets to use a local gas station. In time, a powerful leader brings them together. Drawing on real-life events, the story mirrors Japan's 16th-century civil war, with motorcycles standing in for horses and knives for swords.