She is considered to be one of the best in the business. She was raised as a test subject by her scientist parents who died in the catastrophic earthquake. She was protected by the bustier made by her parents and thus survived. She was then picked up by Aida Gozo, who raised her, and later on she works in Gozo's office as a Salvager.
Aika possesses a unique battle suit made out of 'ultranate' (or more accurately just "alternate metal" from the katakana), shaped into a golden bustier that transforms her into a dark-skinned and blue-haired woman with supernatural strength and resilience. But she dislikes the perfection attained by the transformation and tries not to rely on it. Although not used in the anime, in this form she is called Shivie Aika.
She is constantly fighting with Gust, who either tries to steal her bounty or hits on her. Aika will do anything to get the job done, even if it means sacrificing her morals.