So deku can sing
He has two siblings
Toshinori or toshi midoriya
Izumi midoriya
Everyone who's knows deku can sing is the big three, eri, Kota, all might, jiro, and bakugou
Deku sings too eri when she has nightmares
The big three used mirios quirk to spy on people And they just found out
Kota found out when he walked in on deku singing
Deku told all might
Deku And jiro were childhood friends along with bakugou