A delinquent with a deviation score of "98"! Kaburagi Amaru, a transfer student at the private Seiran High School (commonly known as "Ranko"), rides his motorcycle to school on his first day, and of course, he immediately becomes the target of the delinquents! You'd think he'd be a sure bet for bullies... but Amaru is incredibly strong! That's because he's the 16th generation leader of the strongest gang, the "Bakun Kozo"! The invincible "Bakun Kozo" has finally returned, riding his "crimson CB400F"!