Oh, by the way, i took this from Wikipedia, so thanks to all the wiki-guys :)
Keima Katsuragi, a second-year high school student, is an avid player of gal games (video games that involve interactions with anime-styled pretty girls). He is known on the Internet as "The God of Conquests" (落とし神 Otoshi-gami) for his legendary skills to be able to "conquer" any 2D girl in games. However, in his actual school life, Keima is called otamega (オタメガ), a derogatoryportmanteau of the two words otaku (オタク) and megane (メガネ, glasses).
At the start of the series, Keima receives an e-mail offering him a contract to "conquer" girls and, thinking it is an invitation to a game challenge, he accepts. In response, a cute demon from Hell named Elsie appears: a Spirit Hunter. She asks for his cooperation to help her in catching the evil spirits that have escaped to the Human Realm: the "Lost Souls", which were once Old Demons from Hell. These evil spirits hide themselves inside the hearts of girls, feeding off the hosts' negative emotions to replenish their power and strength, in becoming whole demons once again (which in turn, the host becomes an empty shell of a person). Elsie suggests that the only method to force the evil spirits out is by "conquering" the girls' hearts, making them fall in love with him and filling up the gaps which the escaped evil spirits hide in, in which she is then able to capture them. Interested only in video game girls, however, Keima is appalled by the idea, and refuses the assignment as he has no romantic real life experiences whatsoever. Nevertheless, with the contract already agreed, Keima has no choice but to help Elsie no matter what, as they will be beheaded by an invisible (to others) purple collar around their necks if they fail.
