In their last year of middle school, the five band members of CRYCHIC went their separate ways after an unpleasant disbandment. Each wrestling with their own regrets, the girls enrolled in different high schools, hoping never to hear from one another again. Meanwhile, Anon Chihaya transfers to Haneoka Girls' Academy in the middle of the school year. As most students play in a band as a hobby, Anon desires to fit in and spends her first days trying to recruit members for her own band, envisioning herself as the group's vocalist. She befriends Tomori Takamatsu, a shy girl who seems interested but hesitant about joining. As it turns out, Tomori used to be part of CRYCHIC, an experience that has scarred her deeply. Through Tomori, Anon meets Taki Shiina and Soyo Nagasaki, both former members of the same band. Although Taki detests the idea of playing with Anon, Soyo is delighted to help her out. Now with Soyo by her side, Anon's dream of forming a band is within reach—if only she could find a few more members.

The main protagonist Sendou Aichi, is a timid and mundane third-year middle school boy. The thing that supported Aichi's heart, was the "Blaster Blade" card that he received as a child. It's an important rare card from "Vanguard", a card game with the imaginary world of "Planet Cray" as its stage. From the day he reunited with the person who gave him that card "Toshiki Kai", Aichi's everyday life began to change. (Source: Crunchyroll)