Asuka Sugo, daughter of Sugo Corporation president and former Cyber Formula racer Kojiro Sugo, is the younger sister of Osamu Sugo. She operates as communication staff and occasional acting manager for the Sugo racing team across multiple seasons, stepping in to handle operational duties during managerial absences. Her involvement spans the initial TV series through all OVAs, including SIN.

A childhood friend turned fiancée to driver Hayato Kazami, their relationship evolves significantly. They become engaged during the Zero OVA, though she temporarily breaks the engagement after Hayato resumes racing against his promise following a near-fatal accident. They later reconcile, and she supports his return to competition while pursuing medical studies at Columbia University to aid injured racers. This career path reflects her ongoing concern for driver safety, particularly regarding Hayato and her brother Osamu.

Her role extends beyond team management, frequently providing critical emotional support that influences race outcomes. However, her anxiety intensifies during high-stakes events, notably Hayato's races against Phill in the Al-Zard NP-1 and Kaga in the Ogre AN-21. The relationship progresses to implied intimacy in SIN, contrasting with earlier modesty depicted in the TV series. The series concludes with their marriage, attended by acquaintances from the Cyber Formula world.