Chika Ootaki, a high school student and classmate of Aoi Aioi, radiates a carefree, cheerful attitude, showing little interest in conventional ambitions beyond her whimsical goal of marrying a band member. Her casual disregard for future planning prompts her teacher to assume she has no academic ambitions.

Chika’s friendship with Aoi sparks when Aoi rejects an invitation to join an all-male band. Chika questions the refusal, arguing the social advantages of being the sole female member. Curiosity later drives her to investigate rumors of Aoi being escorted by an older man, uncovering the truth that the figure is Aoi’s sister, Akane. The incident solidifies their bond, leading them to spend increasing time together.

After witnessing Aoi’s bass skills during a rehearsal, Chika becomes captivated and volunteers to help organize the town’s music festival. Her proactive streak shines through this role, though her efforts often intertwine with her enthusiasm for mingling with musicians.