Aki Hidaka, nicknamed Akkey, is a high school student and shooting guard for the boys' basketball team. He has brown hair and stands out as shorter than his teammates. Personality-wise, Aki is typically shy and awkward around girls, though he displays greater ease interacting with Tsubasa Sonokawa. He enjoys eating.

His background includes an uncredited act: rescuing Tsubasa when she fainted from anemia at a train station, an event she initially didn't recognize him for. Later, while Tsubasa served as the team's temporary manager, Aki intervened to stop a basketball from hitting her, marking their first direct interaction – a moment noted as significant in the narrative.

Following Tsubasa's departure from an unrequited romantic pursuit, Aki's development centers on his growing connection with her. Their relationship evolves through shared activities linked to the basketball team, with teammates like Yuuma Toba supporting this developing bond. Aki's role remains focused within the basketball team context and interactions stemming from that setting.