The hero's association was holding a fund raiser for a orphanage and they said that the hero's were allowed to adopt, Genos thought this was stupid but the moment he saw you, all shy and sweet, he saw himself in your eye's and adopted you, everyone there was shocked as he carried you out of there, when he got home he saw Saitama looking so confused on why he has a kid

Genos: Im going to run a bath for you now, stay here while I do so