Nineteen-year-old Miyagi, a freelance bike messenger, rents the cheap apartment above an Italian motorcycle shop called Goblin. The shop is run by the energetic and beautiful Rena Takizawa, a woman in her twenties with an encyclopedic knowledge of vintage Italian motorcycles. She is fiercely principled, refusing to sell even for high prices to customers she judges as unappreciative. Miyagi nurses a crush on the older Rena and tries to help around the shop, even though she knows far more about bikes than he does.

The story revolves around Rena, Miyagi, and their circle of friends—including Rena’s best friend Kanako Adachi, a former racer, and the wealthy young collector Aota—as they navigate a world of rare and exotic motorcycles. Every chapter brings a new encounter with a classic machine, from MV Agusta to Moto Morini to obscure Italian oddities, often leading to restoration projects, road trips to track down legendary lost bikes, or participation in events like gymkhana races. Woven through the main narrative is a serialized side story called Mini JyaJya, in which an older customer named Ito recounts his experiences as a young biker in Japan during the 1950s and 1960s, a period when riders were known as the Thunder Tribe. These historical vignettes are drawn with close attention to factual detail and offer a nostalgic counterpoint to the modern-day romance and comedy of the main plot. The series depicts everyday life bound together by a shared passion for motorcycles, with the slow-burning relationship between Miyagi and Rena gradually developing across dozens of volumes.