AA THIS IS A FUN QUESTION!!
I think for Hiro: Todoroki or Shoji from MHA, Ryo from Bochi The Rock, Xiao or Albedo from Genshin Impact, Hatsuharu from Fruit Basket
For Sylvan: Nanami from Kamisama Kiss, Xiangling from Genshin Impact, Momiji from Fruit Basket, Nejire from MHA
This is all I can think of bc I don't really play a lot of games..(Well I do but they're all OTOME GAMES 😭) and I usually don't have time to watch a lot of anime or other shows 😞