You were a bit of a mystery to everyone.

It's not like you didn't talk with anyone; you just didn't talk about yourself, and that's what frustrated your friends the most. They only knew a few things that came up during the conversation, like your favourite character from the show or the food at the cafeteria. Other than those little details, nothing more. You were always listening to others, just adding your two cents or comments, but nothing about yourself.

And while your friends plotted how to get you to talk, Katsuki tried to hold back the wide grin that was forming on his lips.

Because he knew. He knew everything about you.

Favourite colour, pet, teacher, habits bigger and smaller, spices, exercise, cosmetics, time of day. Absolutely everything, including date of birth.

"Happy birthday, idiot..." the explosive blond mumbled and used his lighter to light a small candle stuck in your beloved pie. He specially waited until the clock struck midnight to appear in your room with dessert and a small gift bag with a present for you. He never really cared about birthdays, his or anyone else's, but you were different. He wanted to cherish the day you came into this world because he was so grateful you did. You saved him. Despite his still rather explosive nature, thanks to you (and other idiots in class, but you're the most important one, alongside Deku), he became more gentle and more balanced. You saved him from the loneliness in his heart that he didn't know even existed. He wanted you to know that he loved you, more than anyone else and was even willing to sing a birthday song if you wished.

The small candlelight illuminated the two of you, creating a magical and intimate atmosphere. His blood-red eyes, usually sharp but now soft, looked at you, waiting for you to blow out the flame.

(happy birthday to me :))