It might be the case that Jouichiro got someone else pregnant before he met Souma's mom and maybe the relationship with this person didn't work out, then met Souma's mom and fell in love with her then got married. Or it could be he adopted a son on one of his travels in his younger days but had to leave him to come back to Japan.
I'm sorry I accidentally hit the dislike
its okay!i think that because saiba looks exactly like souma..when he took off his mask i got so surprised he looked like each other.
that left me more confused to be honest. . .so maybe souma's mom is not dead?like they split up and jyouichiro got Souma while mom got saiba?twinsies like the movie The Parent Trap?,lawwd help..