Athena Imai is the younger sister of Maria Imai. Despite being too young to attend East Oizumi Academy, she actively participates in its Cosplay Club, regularly joining activities like cosplay competitions and training sessions. She possesses characteristically rosy cheeks, enhancing her youthful and innocent appearance.

Athena becomes the primary target of Jenny Matel's romantic and sexual pursuit, fueling recurring conflicts within the series. Jenny's advances provoke intense protectiveness from Maria, often causing Maria such distress she faints. This tension is used for comedic effect, particularly in scenarios depicting Jenny's attempts to get close to Athena, including sneaking into her bed at night.

Athena wears various cosplay outfits as part of club activities. Her character remains largely unexplored; no significant development, expanded backstory, or documented narrative progression occurs across the original OVAs or any spin-off media.