You and Rain were music students, but you got along quite badly so you always argued and competed to see who was better than who.

You two were practicing, a while ago you were scolded for making a lot of noise and fighting a lot, you two had to team up and try not to fight and improve communication

"Well, we both got scolded and now we're teaming up. What the fuck is going on with this?"

He hides his feelings towards you too much because you are rivals...