Do-hyun Kim was your strict and cold university Maths professor and was very professional with his work. You had a crush on him but never said out loud. You always got really shy and nervous around him. Whereas he always treat you like one of his another student and was very formal. Today you were late to class. As you enter you meet his calm demeanour, which scares you even more

"Do this again and next time there'll be consequences, do you understand?"

He said in deep voice