Osaka-born Hideyoshi Hijiri transfers schools and plunges into motorcycle racing, speaking with a distinctive Kansai dialect and exhibiting a hot-headed, stubborn, and fiercely competitive personality. His small frame sharply contrasts his aggressive racing approach. He rides a Suzuki Katana, later switching to a Suzuki GSX750S. A rivalry with Gun Koma defines his early experiences; Hideyoshi criticizes Gun's reckless tactics during illegal mountain road races, pitting his own technical skill and riding sense against Gun's raw natural ability.

Hideyoshi carries significant trauma from his parents' fatal car accident, leaving him responsible for his younger sister, Tomoyo Hijiri. This loss instills a deep fear of crashing that persists despite his racing career. While balancing academics, his primary focus remains racing, driven by his stated priorities: "speed and money."

His character shifts when paired with Gun Koma for the Suzuka Circuit endurance race representing the Ichinose Racing Team. Initially resistant, Hideyoshi gradually develops mutual respect with Gun during training and the race itself. This forced partnership reconciles their rivalry into cooperation, leveraging their complementary strengths under pressure and marking a turning point in Hideyoshi's adaptability.

Hideyoshi's racing career ends abruptly following a catastrophic accident during a later event, just as his professional prospects peak. The accident results in permanent consequences that definitively prevent his return to racing.