No Bra follows the life of some duder whose old elemetary school friend came to be roomates with him....but its a hot girl, or is it?!
I think you should read "Namida no Sumasshu aka Smash of Tear" written by Urasawa Naoki!
If you like My Girl, then I'm sure you'll like Usagi Drop. Only issue is that it hasn't been updated in a while. The scanlations end at the 'first part' of the manga.