Jun Hyung and Yo Seob have been best friends since young. 

List of things Jun Hyung DOES know about Yo Seob:

-Yo Seob has always stuck with him through thick and thin.
-Yo Seob is no bad boy but he still hangs out with Jun Hyung and Dong Woon who are pretty much the school's worse bad boys.
-Yo Seob is an excellent dancer.
-Yo Seob is mad romantic.

List of things Jun Hyung DOESN'T know about Yo Seob:

-Actually, there's only one. Yo Seob is in love with him.

The thing is, Jun Hyung himself is in love with the class beauty, Jang Hyun Seung and Yo Seob knows because Jun Hyung was pretty much dating Hyun Seung till Hyun Seung broke up with him 2 months ago. And now... enter! New kid Lee Gi Kwang! Jun Hyung needs to fend of Gi Kwang while trying to gain Hyun Seung's attention and he begged Yo Seob and Dong Woon to help him.

If only he knew how painful it was to help the person you love get someone else's attention.