Miku Maekawa, a 15-year-old Osaka native standing 152 cm tall, celebrates her birthday on February 22. Her love for cat cafés fuels a playful feline persona, sparking rivalry with Nana Abe due to their overlapping animal-themed identities. Despite their clashes, Miku supports Nana’s decision to maintain her Usamin persona against external criticism. Stubborn yet fiercely just, Miku confronts perceived injustices head-on, such as publicly challenging unearned opportunities given to fellow idols. Her relentless advocacy drives both conflict and camaraderie, paired with a passionate—if superficially informed—enthusiasm for rock music, earning her the playful fan nickname “poser.”

Central to her story is her evolving bond with Rīna Tada. Initially forced into the unit “* (Asterisk)” as reluctant partners, their tension gradually transforms into mutual trust. This dynamic frays when Rīna gravitates toward Natsuki, a guitarist embodying her rock ideals, leaving Miku feeling overlooked. Miscommunication spirals into self-blame, pushing Miku to pursue perfection to avoid disappointing Rīna. Their strained relationship ultimately weathers these trials, reinforcing their partnership.

The anime’s second season explores Miku’s hidden vulnerabilities as she fears their unit’s collapse, particularly Rīna’s potential departure. Later portrayals, like Rīna’s “Blue Sunshine Summer” card, depict their reconciliation through collaborative performances, emphasizing their unbreakable connection.

Miku’s physical traits—45 kg weight, blood type B, and measurements B85-W55-H81—subtly inform her design without overshadowing her narrative journey.