It's MyGO!!!!!, but I Have a Tycoon System

[Band-Girl Anime Fanfiction: What if all the band girls lived in the same world?]

The legend of Yutenji Haruna lives on forever in the hallways of the Metropolitan Art Academy's Tachikawa High School.

She has a doll-like baby face that makes her look like a middle schooler. No one knows that this legendary girl, whose public image contrasts so sharply with her private life, is the keyboardist of Kessoku Band at the STARRY live house in Shimokitazawa.

Holding her little sister Nyamu's hand, she stumbles into the youth of four girls. They rehearse again and again in the evening breeze of Shimokitazawa, play passionate melodies under the spotlights, and stand shoulder to shoulder with their companions as they steadily pursue a dream called becoming the best in the world.