In the near-future, the world's energy problems have been solved thanks to a scientific power known as the Manifestation Engine which provides energy from the sky. On the island of Izu Oshima, Akane Isshiki is living a simple life with her sister, Momo, and her grandfather and creator of the engine, Kenjirou. As Akane eagerly awaits the arrival of her classmate, Aoi Futaba, who is travelling to the nearby Blue Island for treatment, she and Momo hear an explosion coming from their home and discover that Kenjirou has somehow switched bodies with an inanimate ferret doll as the result of an experiment. Undeterred by his new form, Kenjirou gives Akane his latest invention, a strange key, in order for her to fight against a strange alien mech, known as an Alone, that is attacking Blue Island, where the Manifestation Engine is stored. As Aoi's transport is hit and crash lands on a ledge, Akane and Kenjirou rush to their location, but Akane is soon struck by her fear of heights that she gained during a traumatic incident. When Aoi starts to fall towards the sea, Akane overcomes her fear and dives after her which activates her key, giving her a special suit known as the Vivid System which stops Akane and Aoi from falling. Kenjirou explains that this system is for Akane and Aoi to fight against the Alone.
誰もが夢見た、科学が全てを解決した、平和な時代―
示現エンジンの発明により世界中のエネルギー問題は解消していた。
天真爛漫な14歳の少女・一色あかねは、妹・もも、祖父・健次郎、と貧しくも温かな日々を過ごしていた。
ある日、親友・二葉あおいの帰りの知らせを受けたあかねだったが、時を同じくして突如現れた謎の存在・アローンの襲撃にあおいが巻きこまれてしまう。
あおいを心配して迎えに行くあかねだったが…。
세계의 에너지 문제를 해결한 시현엔진의 발명으로 모두가 평화로운 시대를 만끽하고 있었다.
그리고 블루 아일랜드에 사는 14살의 소녀, 잇시키 아카네도 가난하지만 즐거운 나날을 보내고 있었는데.
그런데 어느 날, 블루 아일랜드에 시현 엔진을 노리는 적, 아론이 나타난다!
En un futuro cercano, los problemas energéticos del mundo se han resuelto gracias a un poder científico conocido como Manifestation Engine, que proporciona energía desde el cielo.
