In 2005, Shizuku was innocently studying in school when her world went up in flames—literally. Having been hurled out of Unicron by Rodimus Prime, the Decepticon leader Galvatron's voyage through space came to an end when he violently crash-landed on Earth in the middle of Tokyo, reducing the city to a smoldering crater and killing Shizuku, among millions of others. The loss of her daughter transformed Shizuku's mother from a mild-mannered scientist into a fervent anti-Transformer campaigner who was instrumental in the formation of the anti-Transformer organization, the Earth Defense Command.
Soon, it was discovered that Galvatron's Unicron-empowered cells had been scattered across the planet, fusing with other lifeforms to create monstrous creatures known as Legion and super-powered humans that the EDC recruited and trained as Kiss Players. Discovering that the essence of her daughter had somehow been infused into the Legions along with their Galvatron cells, Hitoshizuku's fractured mind conceived of a plan to resurrect Shizuku in the body of a Kiss Player. Experimenting with Galvatron's corpse, severed Legion body parts and Kiss Players who had outlived their usefulness in the secret Genital System beneath EDC headquarters, Hitoshizuku also observed a girl named Atari Hitotonari as a potential subject for the process. She thus recruited her into the EDC when Atari proved to possess particularly potent Kiss Player powers.
Ultimately, Shizuku was never revived, as her mother's mad plan was stopped by Atari, Shaoshao, Hot Rod, Marissa Faireborn, and Optimus Prime. Galvatron's cells were removed from the Kiss Players and Legion, and the reconstituted Decepticon leader was shot back into space, as Hitoshizuku met her own end, reuniting with her daughter in the great beyond.