Rito is a high-school boy who just can't confess to the girl of his dreams, Haruna-chan. One day when coming home and sulking in the bath-tub a mysterious, and barely clothed girl, appears out of nowhere. Her name is Lala and she comes from another planet...
A bit cliche, but actually reading the first three chapters, I found myself laughing quite a bit especially in chapter 3. It's by the same artist who did Black Cat and I believe the manga is pretty new in Japan. It's currently being scanlated by Aerie and KEFI.
Of course there is a lot of naked cleavage, misunderstandings, etc etc for you Love Hina, Ichigo 100% types out there (and people seem to ask for this kind of manga here quite a bit). But the thing that I enjoy about this manga so far is the humor. Give it a try.
Summary from mangaupdates.