OVA
Description
Aika Sumeragi works as a salvager for the small company K.K. Corporation (K2), run by Gozo Aida and his daughter Rion Aida. Her scientist parents, lost in a catastrophic global earthquake that submerged much of Tokyo and other landmasses, previously subjected her to experiments with a unique "ultranate" metal. This metal was integrated into a golden bustier they designed, which she later inherited. Gozo Aida rescued and raised her after her parents' death, training her in salvaging.
The ultranate bustier enables a transformation that changes her physical appearance, granting enhanced strength, speed, and resilience. Upon activation, her skin darkens, her hair turns blue, and her eyes shift from green (in earlier appearances) to blue. The metal forms a battle bikini, replacing her regular clothing except for her shoes and collar. This process tears away her garments, leaving her partially exposed after reversion. The transformation also generates combat tentacles for offense or defense. However, the metal can activate involuntarily during high-stress situations, potentially overriding her consciousness. In this state, her eyes turn gold, her voice deepens, and the metal takes control—referred to as "Shivie Aika" in non-anime material. Aika avoids using this ability due to the risk of permanent loss of autonomy and the embarrassment of post-reversion nudity.
Her background differs across official timelines. At age 16 in "AIKa R-16: Virgin Mission," she starts salvaging under Gozo's guidance while attending school, assisting in missions involving classmate-related mysteries. By age 19 in "AIKa ZERO," she carries non-lethal weapons and investigates disappearances linked to a substance called Lagu, hinting at a latent connection to her experimental past. In the original timeline at age 26, she undertakes high-risk salvage missions, including recovering Lagu—a material her parents studied that triggered the global earthquake. This mission involves conflicts with antagonists like Rudolf Hagen and his female army, the Delmo Corps, created to repopulate the world.
Her relationships include a familial bond with father figure Gozo and a mentorship role toward Rion, who aspires to emulate her. She has a contentious dynamic with fellow salvager Gust Turbulence, who frequently competes for bounties and makes romantic advances that she rebuffs. Professionally, she prioritizes mission success, sometimes disregarding ethical boundaries.
In the 12-minute bonus episode "AIKa: Special Trial," she participates in relocating K2’s office, featuring transitional footage and musical sequences without substantive character development or narrative advancement.
The ultranate bustier enables a transformation that changes her physical appearance, granting enhanced strength, speed, and resilience. Upon activation, her skin darkens, her hair turns blue, and her eyes shift from green (in earlier appearances) to blue. The metal forms a battle bikini, replacing her regular clothing except for her shoes and collar. This process tears away her garments, leaving her partially exposed after reversion. The transformation also generates combat tentacles for offense or defense. However, the metal can activate involuntarily during high-stress situations, potentially overriding her consciousness. In this state, her eyes turn gold, her voice deepens, and the metal takes control—referred to as "Shivie Aika" in non-anime material. Aika avoids using this ability due to the risk of permanent loss of autonomy and the embarrassment of post-reversion nudity.
Her background differs across official timelines. At age 16 in "AIKa R-16: Virgin Mission," she starts salvaging under Gozo's guidance while attending school, assisting in missions involving classmate-related mysteries. By age 19 in "AIKa ZERO," she carries non-lethal weapons and investigates disappearances linked to a substance called Lagu, hinting at a latent connection to her experimental past. In the original timeline at age 26, she undertakes high-risk salvage missions, including recovering Lagu—a material her parents studied that triggered the global earthquake. This mission involves conflicts with antagonists like Rudolf Hagen and his female army, the Delmo Corps, created to repopulate the world.
Her relationships include a familial bond with father figure Gozo and a mentorship role toward Rion, who aspires to emulate her. She has a contentious dynamic with fellow salvager Gust Turbulence, who frequently competes for bounties and makes romantic advances that she rebuffs. Professionally, she prioritizes mission success, sometimes disregarding ethical boundaries.
In the 12-minute bonus episode "AIKa: Special Trial," she participates in relocating K2’s office, featuring transitional footage and musical sequences without substantive character development or narrative advancement.