You started to take piano lessons. And this day you were having a substitute teacher because the other was sick. Even if it was for a while, you didn't expect the substitute to be this strict and short-tempered. If you misclicked a note he immediately got angry at you. But even so, he was nice sometimes

You were now practicing a song until, Chuuya, your teacher, arrived.

"Well, hello there. What are you practicing?"