Hitori Gotou, a lonely high school freshman crippled by social anxiety, has spent years mastering the guitar under the delusion that musical talent would bring her friends. Despite her skill and an online persona called Guitar Hero that garners thousands of views, she remains unable to speak to her classmates. Her world changes when a drummer named Nijika Ijichi, desperate for a last-minute fill-in at her band’s live show, happens to spot Hitori carrying her instrument. Although Hitori’s first performance inside a cardboard box is a disaster, Nijika sees her potential and formally invites her to join Kessoku Band.

The band operates out of Starry, a live house in the Shimokitazawa district run by Nijika’s older sister, Seika. The other members include the eccentric and perpetually broke bassist Ryou Yamada, who originally founded the group with Nijika, and Ikuyo Kita, a popular and outgoing girl who initially joined to be near Ryou but fled after lying about her guitar skills. Kita returns as the band’s vocalist and rhythm guitarist, becoming Hitori’s first real friend from the same school. The central narrative follows Kessoku Band as they navigate the realities of the indie music scene, from playing to near-empty rooms to working part-time jobs at Starry to fund their activities. A significant early arc involves Hitori composing an original song for the band to gain more credibility, a process that forces her to confront her insecurities directly. Later, the band participates in a major teenage rock festival audition called Mikakunin Riot, where Hitori must overcome a crisis of confidence after a rival band delivers a stunning performance. Throughout these experiences, the series explores the small, incremental victories of managing mental health, from ordering coffee to making eye contact, as Hitori slowly learns that connection is a practice, not a cure.