High school student Hitori "Bocchi" Gotou has no social life or any friends—unless you count her guitar. She dreams of creating a school band in the hopes that using her instrument will elevate her social standing. However, despite spending the last two years diligently practicing guitar, she is no closer to her goal.

Although she has gained a following online for her guitar covers of popular songs, Bocchi's lack of social skills means that her dream may ultimately be impossible. But one day, drummer Nijika Ijichi spots Bocchi with her guitar alone in a park. Desperately in need of a guitarist, Nijika quickly recruits Bocchi to the band that Nijika has formed with bassist Ryou Yamada—Kessoku Band. Though overwhelmed and left floundering at the sudden social interaction, Bocchi realizes this may be the start of something bigger.