Anime does this thing where it's painfully obvious who is a main character and who isn't, and one of my favorite "examples" of this is how Giyuu has so much survivers guilt surrounding Sabito, and if you were to put Giyuu and Sabito next to eachother and ask someone who didn't know the characters who the main character was, nobody would say Giyuu because he just looks like an extra.
the only "main character" thing about him is his haori, which belonged to Sabito
It's almost like his entire character design is a nod to the fact that he was never supposed to make it past final selection










