Me: *Looking at black-haired children.*
Everyone else: "Don't you dare tell him."

Selvokaz said:

Me: *Looking at black-haired children.*
Everyone else: "Don't you dare tell him."

Naw, man. Kirishima's hair is dyed; you see that it's naturally black in the flashbacks.

(It's also not naturally spiky; it's both dyed and gelled!)

user_536050 said:

Naw, man. Kirishima's hair is dyed; you see that it's naturally black in the flashbacks.

(It's also not naturally spiky; it's both dyed and gelled!)

So his and Mina's kid with red hair here idolizes Eijiro, which is why it fits his siblings who have Eijiro's hair have his natural black hair!