Manga about teenager taking care of a kid

I'm looking for a manga where this guy has to occasionally take care of a kid (not Aishteruze Baby, or Usagi Drop). It's an ordinary slice of life, not yaoi or romancy... Crumbs, i really wish I'd have bookmarked it, cos I only remember that the kid had black hair and kept quiet because he did not like to burden adults. And the teenager who he got attached to was this spacey capricious guy who most would call a good for nothing, but he was a good guy.
Anyone know this one? Please and thank you~