I've said it here before and I'll say it now, the Japanese can be muy weird. It's like the knob sometimes fall off on their volume control for strange and it's left at 11.5. Dating Sims are a good example of this. It's a sub genre of Japanese gaming that is just plain strange. Guys try to seduce digital girls by manipulating the situation and their feelings. Yeah, sort of a groddy feel just describing these things. "The Worl God Only Knows" take the world of dating sims and runs with it.
Our hero is a geek who plays these games so well and so often he's called by fans "The God of Conquests." In real life he's a geeky nerd who dresses emo goth and doesn't really have any interests in girls in reality. One day he accepts what he believes to be a challenge from some anonymous email. Bad move charlie, what he accepted was a deal with the devil. This is explained to him by a pretty female demon with a broom. The details are this, there seems to be a lot of loose souls running around. They are hiding inside the hearts of pretty girls and the only way to free them is to open their hearts as demonstrated by a freely given kiss. Our hero either does this, or he gets a head shorter. Let the games begin.
The problem is that of course reality is not a game. He finds himself stymied by simple things like the girl track team not having their hair up. Everyone of course knows that girls on track team have their hair up. Luckily his demon can change reality in little ways like that which everyone finds very weird. He then tries to put his moves on real women with on again, off again success. Of course he wins his kisses and loose souls, but the real question is will the hero stay a proto-sociopathic geek or will he somehow learn to really connect with people?