Miku Maekawa is a 15-year-old student and idol from Osaka with dark brown hair, green eyes, standing 152 cm tall, weighing 45 kg, and possessing blood type B. Her birthday is February 22. She exhibits an energetic and stubborn personality, often demonstrating an unbending spirit and fierce determination to achieve her goals, such as organizing a holdout protest over perceived unfairness in debut opportunities. Her interests include visiting cat cafes. She passionately identifies as a rock music fan, though her limited knowledge of the genre leads fans to jokingly label her a "poser."

Her most significant relationship is with Rīna Tada. Initially paired in the unit *Asterisk*, they disliked each other but forged mutual trust and warmth through forced collaboration, developing a deeply intimate relationship marked by frequent arguments balanced by underlying respect and understanding. This dynamic shifted when Rīna became enamored with Natsuki, a guitarist embodying Rīna's "rock idol" ideal. Natsuki encouraged Rīna's rock interest, causing Rīna to emotionally withdraw. She began arriving unprepared to meetings and dismissed Miku's concerns. Miku internalized this rejection, blaming herself and striving for perfection to avoid holding Rīna back, leading to severe communication breakdown and plunging Miku into intense depression, especially when she assumed Rīna would leave Asterisk. Despite this turmoil, she persevered and emerged stronger. Their relationship also included lighter moments, like playing together at the beach depicted in Rīna's "Blue Sunshine Summer" card.

Miku notably interacted with Nana Abe, viewing her as a rival due to their similar animal-themed personas. Miku played a key role in convincing Nana to retain her "Usamin" persona after being instructed to drop it. Miku's development centers on weathering emotional hardship through resilience, specifically enduring the depression and self-doubt caused by the rift with Rīna, culminating in renewed personal strength and perseverance.