Dong Sicheng or Winwin was once a cheerful child but after returning from his auntie's province he changed

The cheerful one became cold

The one who cares for others before himself is now gone

He changed a lot 

Nakamoto Yuta is a transfer student in Seoul High

He likes to talk a lot which annoys him

but he didn't thought that they would be friends 

Then one day he just knew that he saw the light 

That brought back the old him