Rion Aida (相田りおん Aida Rion) is the 18 year old daughter of Gozo Aida and the salvaging partner of Aika Sumeragi. Although at times, Rion just appears to get on Aika's nerves, Aika has been shown to care about her very much, as shown when she risked her life to save her from the Delmo Corps.
From Dvd: She´s a female James Bond: Spunky, tough and competent. She has a knack for getting into situations and finding resourceful solutions.
Rion has the appearance of an 18 year old girl, with chestnut brown hair, which is almost shoulder length, glasses, and like many other females in the series, has medium breasts. In the beginning of the series she wears a yellow tank top over a white, buttoned, collared shirt, a green skirt, white panties, and red boots with yellow bows. Throughout the series, she also wears a Black Delmo uniform and a Blue Delmo uniform.
Despite having no combat training whatsoever, Rion Aida shows she is able to come on top in multiple situations in which logic would say she should be defenseless, even outnumbered or against trained soldiers. Examples include:
- In Trial 4, Rion makes quick work of Catherine when the Blue Delmo is escorting her to her cell. Despite being handcuffed, the teenager is somehow able to gain the upper hand and beat the girl unconscious, later stripping her of her uniform. Afterwards in the same episode, she manages to surprise Naomi and knock her out with a blow from the back just as the unsuspecting Black Delmo is about to call for reinforcememts.
- In Trial 5, Rion singlehandedly takes care of Balck Delmo Saori, who she engages in a fight all by herself. At first both girls find themsleves in a deadlock, unable to gain the upper hand over one another. Eventually, however, Rion finds a way to break the stalemate by hardly stepping on Saori's foot, causing the girl to cower in pain. The distraction gains her enough time to finish the Black Delmo off with a devastating blow to the girl´s face as she is trying to recover.
- In Trial 6, Rion is not only able to expose the identity of the 2 Black Delmos (Delmo Employees A and B) who had had been assigned to keep an eye on her and Shuntaro, but also to dispatch both girls all by herself. Though it´s slightly a matter of luck, as the soldiers are knocked out as a result of a humorous fall down the stairs, the fact remains that Rion is the one to cause said fall and she also survives the incident, resulting thus the final winner of the rather comic altercation.
- Rion's surname Aida means "fellow" (相) (ai) and "field, rice paddy" (田) (da).