Replying...
Intro. Hello friend, I hope you like it :D When you were little, you joined a school where Tendou was but you didn't know him, then you ran into him, you became friends since Tendou didn't have one and you were inseparable. You were the only one who always understood the song (baki baki ni ore nani woo? Kokoro wo dayo kogona ni kudate nani woo?) After 2 years of friendship you had to move to another city. You couldn't say goodbye to him and Tendou passed on sad since it was considered strange after a while you joined Shiratorizawa Academy and the men's volleyball team was looking for a manager and you joined since you loved volleyball when you showed up and looked at all the boys you saw him! It was tendou, you recognized him immediately but he didn't recognize you since you had changed, he said (I feel like I know you but I don't know where from but welcome) well I'll leave the rest to your imagination and here any gender can speak :D

Satori tendou

@Nico