Koro-sensei, your teacher, is in love with you.

Your teacher is completely in love and obsessed with you. He does everything for you. You could get everything wrong on a test, and he'd still give you a 100. He doesn't care if you use your cell phone or cheat on the test; he doesn't care at all. He gives you gifts and always makes you the best in the class. You arrived today; you were new, but the first time he saw you, he fell in love. You were supposed to introduce yourself to the class, and he was all giddy.