Yonkuro Hinomaru stands as the central protagonist throughout the Dash! Yonkuro franchise. His journey into Mini 4WD begins in childhood upon receiving a Boomerang Jr. car from his father. Initially dismissing the hobby as trivial, a formative experience with his father ignites a lifelong passion for competitive Mini 4WD racing. This fervor defines his core identity: marked by hot-blooded enthusiasm, relentless determination, and an unwavering belief in Mini 4WD as serious competition. He actively confronts anyone viewing the sport as childish or insignificant.

Physically, he appears as a young boy sporting black hair cut to ear length and blue eyes, frequently accessorized with a headband and wristbands. His racing style embraces high-risk maneuvers focused on ultimate track efficiency, constantly pushing his cars beyond mechanical limits. This aggressive approach necessitates frequent car replacements and upgrades throughout his career.

Yonkuro's path centers on founding and leading the Dash Warriors team. Key bonds form within this group: Dankuro "Tankuro" Toda evolves from rival to best friend after Yonkuro retrieves Tankuro's Hotshot Jr. from the ocean. Shinkuro Minami, initially solitary, eventually joins after recognizing friendship's value through racing against Yonkuro. The team benefits from the mentorship of Coach Kaidanji Sumeragi, a scarred former Formula 1 designer who provides technical expertise, particularly following his involvement in a catastrophic rally event.

His progression is chronicled by a sequence of signature Mini 4WD machines, each marking technological and performance leaps. In the original series, his vehicles evolve from the Boomerang Jr. through the Dash-1 Emperor, Dash-01 Super Emperor, Dash-001 Great Emperor, Liberty Emperor, and finally the Geo Emperor. The Liberty Emperor features prominently in the Hell Rally arc, where Yonkuro confronts his father, Genkuro Hinomaru, piloting the Dash-0 Horizon Boundless. This high-stakes race serves as the narrative climax, resolving long-standing familial themes.

The sequel series, Hyper Dash! Yonkuro, reintroduces him piloting the upgraded Rise-Emperor, engineered with a midship AERO (MA) chassis for enhanced aerodynamics and speed. His ageless appearance across decades is explained as a consequence of dimensional travel orchestrated by the "girl of Dogu," suspending physical aging. His original team members return with upgraded vehicles: Burning God Sun (Tankuro), Shooting Proud Star (Shinkuro), Cannon Dead Ball (Kouji "Punkuro" Jimi), and Dancing Divine Doll (Rinko Sumeragi).