aid of this mysterious 'power-up', Tsubasa is able to defeat the monster, despite it being somewhat accidental on her part. When the battle is over, Tsubasa reverts back to her normal form, but the strange substance turns into an visually identical copy of herself upon separation. The alien awakens, and together, all three return to Tsubasa's house and stay the night in her room. The next day the alien introduces himself as D.D. and explains that he was transporting the seeds of a monster called a Maguar, when one of the seeds hatched and attacked him, forcing his ship to crash land on Earth. The copy of herself, who claims the name of Hikaru, is a type of combat suit called a Figure that for some reason has assumed its current form, and has all of Tsubasa's memories. The real problem is the Maguar Tsubasa had defeated was only one of the six Maguars D.D. was transporting; the others were now scattered somewhere throughout Hokkaidō. D.D. eventually realizes he will need the girls' help to destroy the remaining Maguar, as earth's atmosphere has enhanced both Hikaru and the Maguar in a similar way, while he waits for reinforcements. To facilitate the problem of suddenly having a twin that no one knows about, D.D. decides to modify the memories of Tsubasa's father, making him believe he had twin daughters all along, and that Hikaru was simply living elsewhere with an aunt. Passing himself off as a visiting photographer friend, D.D. proceeds to monitor the Maguar from his ship, while Tsubasa and Hikaru live together at Tsubasa's house, go to school together at Tsubasa's school, fight together as Figure 17 against the Maguar, and essentially become siblings in a more emotional sense. Characters Main characters A shy and timid 10-year-old girl originally from Tokyo. Her mother died during childbirth, leading Tsubasa to sometimes blame herself for her death. Her self-esteem slowly improves after coming into contact with the artificial being that names herself Hikaru. A , or a techno-organic being that fuses with its user to become a , an advanced battle armor. When she first comes into contact with Tsubasa, they combine into Figure 17, whose abilities surpass those of other Figures. Instead of reverting into her dormant state, the Ribers becomes a clone of Tsubasa and calls herself Hikaru. In contrast to Tsubasa, Hikaru is more lively and outgoing. A