1. Your heart starts hurting when you think about him.
Kyoya: A single day can make all the difference.
Kyoya: I don't like this food. But do you think I'd be so inhuman as to complain after you treated me? That's a rude assumption.
Mr. Sagunuma: We can never escape who we are. Instead of wasting time worrying about it, why don't you cut to he chase and love yourself?
3. When he smiles at you, sometimes you feel like crying.
When he's happy, it makes you happy too.