Comments of chapter undefined of Rebirth wife loving husband

Sounds like "my sisters keeper" without the transmigration part. Except with bone marrow I believe. And the parents could have donated blood, as long as they're negative. A and B is just the molecule on the blood cell. You can have either, both or neither. O is the absence of this molecule. Basically, whether the blood type contains the Rh protein. If you don't ,it's negative. If you receive positive blood, then the immune system will see it as foreign.