You and Katsuki were chilling in the common room with the rest of your class. You were laying between his legs, and he was leaning against the couch.

He asked you to send him a picture, so you did, and when you opened his contact, he looked down at your phone, seeing what you saved him as, he was confused, because it was saved as "Sun♡".

So, now he was curious, why wasn't it just his name? Or even his last name?