It’s kinda inferred in the first chapter? They are both orphans at the same orphanage supposed to be similar age, where adoptive parents are only looking for their child based off of the 2 signs and age based on what they saw at birth. The only thing they have similar is eye color and a mole in the same place which can literally come from anyone, it’s not like it’s a sure sign someone’s related without looking at the genotypes. They have completely diff hair, skin, and height, otherwise.

Are they actually related? They have the same eye Color and mole on the nose