Vividred Operation

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 Kenjirou instructs Akane and Aoi to undergo 'docking', Aoi receives her own Ignition Key, allowing her to also transform using the Vivid System. Receiving weapons to go along with their new abilities, Akane and Aoi begin fighting against the Alone whilst protecting the innocent. Meanwhile, Kenjirou contacts the head of the Manifestation Engine's management bereau, Yuuri Shijō, in order to gain military support in assisting the girls in fighting the Alone. After knocking out the Alone's core, stopping its movement, Akane and Aoi attempt the Docking Operation, but it fails due to one of them subconsciously rejecting the fusion. As Aoi worries that she might be the one causing it to fail, she thinks back to when she first became friends with Akane, who gave her a tomato on their first meeting. Meanwhile, a mysterious girl fires a glowing arrow into the Alone, bringing it back to life and changing it into a more powerful form.