Souji has scars all over from his childhood. No one will ever convince me otherwise. There’s no way you go that long with being beaten and abused and never had a scar on you. Hehe. My Souji has them all over his back, his arms, etc. Where ever he could be beaten black and blue without it being seen.
Not only that but samurai are bound to get them from work. And it would explain why Souji was so well covered up ahahah, just kidding.