Saya Akabane is Aya Akabane's older sister. She rides with the bosozoku biker gang led by Kaname Oku, who also teaches at Gokurakuin Girls' High School. Despite her gang affiliation, Saya consistently presents a sweet, gentle, and polite personality, nearly always smiling. This gentle nature juxtaposed with her delinquent connections creates a striking contrast.

Aya Akabane exhibits intense fear towards Saya, stemming from Saya's biker gang ties and the group's intimidating reputation. This fear persists regardless of Saya's outwardly kind and unthreatening demeanor. Their relationship centers on Aya's trepidation, unexplained by any overtly aggressive actions from Saya. Their names share similar phonetic endings ("Aya" and "Saya").

Saya Akabane's documented role remains consistent as Aya's feared older sister, characterized by her dual association with gang activity and a disarmingly calm disposition.