Trying to ID an anime in which a guy ends up adopting his .. Half-sister, I think. An old man dies and his family finds out that he has a young daughter nobody knows about, nobody wants to adopt her and a single man steps up and adopts her. ( Judging anime videos and none of us can recall the title!)
The Promoted to Parent page of TV Tropes didn't help much.
The Promoted to Parent page of TV Tropes didn't help much.