Well....
Mild spoiler....
he consider them his kids and just this ch one of them said "let's get married" (cuz she wants to be family with him since they are not blood family tho he already consider her family a.k.a daughter) and he just think of it as young child going around saying "i'm gonna marry dad when i'm grow up" and i'm most definitely sure even if any of them try something similar he will continue to have that same attitude but still...

does tgis have any harem or romance?