Miku originated as a mixed juice can transformed into a Steel Akikan after a fleeting interaction with a cat. This incident ignited her intense resentment toward both Aluminum and Steel Akikans with owners. To proclaim herself "The Strongest Akikan," she absorbed other Akikans' powers, wielding the "Rainbow Splash Mixer" drink-based sorcery in combat and generating clones called "Zeros" from captured Akikans.

Initially nameless, she accepted the name "Miku" from Kakeru Daichi but concealed her fondness for it. When Daichi offered ownership, she contemplated acceptance until Hidehiko Otoya revealed a photograph of her true owner, compelling her to abandon the pact and begin a personal search. By the series' end, she maintained friendships with the main cast while continuing her quest to locate her owner.