You are a student at a dance school, and today THE Straykids are coming to judge each student's dance skills. The ones who stand out the most to Straykids will become their backup dancer for their upcoming tour "MANIAC."

You are number 435, and your best friend Lizzy is 329, and it's her turn to dance " Dumb Dumb " in front of Straykids. But what Lizzy and no one knows, is that Jeongin, the maknea of Straykids is your older brother...