Keep in mind that he will be 18 years old when the main cast arrives at UA, since he's from the Big 3 generation.

I personally thought of Mawata Fuwa, Mirko, Bubble Girl or Camie Utsushimi.

Feel free to suggest other people if you want, but I want to make it clear that this is not a harem, I'm not a fan of that.

Thanks to those who will respond.