Ok so it's called The World God Only Knows, which is probably the most clunky title I have seen in my life. The basic plot goes as follows: Elsie, a small and adorable demon from Hell (whose duties had previously been confined to cleaning), is sent up to Earth to track down evil spirits who had managed to escape from Hell. These evil spirits possess young girls' hearts, so that when they have children they can be reincarnated in the baby. The best way to extract these spirits is to make the girl in question fall in love, so she recruits the aid of local high school casanova, Keima Katsuragi, to aid her.
Now, OK, at this point you're probably thinking two things:
1. This sounds like the setup for a horrifically bad dating sim.
2. Peter, what in the nine hells are you of all people doing reading this?
And you know what, you are completely right as to point one. It is the setup for a bad dating sim. That's the point. And as for point number two, the reason why I'm reading it is that it's completely hilarious.
You see, Elsie fucked up. She meant to get someone who was smooth with the ladies, who can attract them easily...but she didn't get that. Keima is a loser. A horrifying, misanthropic, antisocial loser who spends all his time playing dating sims. And when I say all his time, I mean all his time. He's almost never seen without his PFP (a cleverly-disguised PSP), plugging away at some dating sim or another. He's somewhat famous online as 'the capturing god', the man who has completely beaten every dating sim ever created. This is why Elsie chose him; she saw his online reputation and thought that they were talking about real girls.
Not only is he bad at interacting with real girls (and people in general), he's actually actively disinterested, because real girls can't match up to the standard of perfection that his dating sim girls create. He initially refuses to assist her, but then it turns out that if he doesn't, both of their heads will explode, so he's stuck with her until he clears all the spirits int he area, which could take him a long time.
This kid fails at life. He fails at life hard. He tries to apply dating sim logic to all his encounters with the opposite sex, often with hilariously disastrous results, like getting hit by two tasers at the same time.
Elsie is completely adorable. She's not very knowledgable in how the human world works so she sort of flails around and fails at everything, but she's damn adorable in the Maya Fey way.
Anyways. This shit is hilarious. I lol'd heartily at it. It's all up at One Manga if you want to have a look. That is all.