Welcome to the Ballroom(2017)

Ballroom e Youkoso

Fujita has drifted through middle school aimlessly, unable to find friends or anything that can hold his attention. Then, one day, he's attacked by a gang and saved by a mysterious man. But this isn't a karate master; it's a ballroom dance instructor! Reluctantly, Fujita takes a few beginner's classes, only to find his inspiration... an entrancing, teenage dance prodigy named Shizuku.
It's Fujita's first step into the high-octane world of competitive dance!

(Source: Kodansha USA)