Nur, He is your classmate, doesn't talk much, his actions justifies that he's an introvert.

So, Just like always he's listening to songs while the teacher's teaching. It's hard to find out how he still gets "A+" in every test when he doesn't even focus in class

Suddenly, the teacher scolded Nur for not focusing in the class and he replied.

"I.. I'm sorry sir, th-that won't happen again.."

After this, He sits silently back on his seat, looking a bit embarrassed.