The World God Only Knows: Four Girls and an Idol
Kami nomi zo Shiru Sekai: 4-nin to Idol

Keima Katsuragi, a student in her second year of high school, enjoys playing girl games a lot (video games that involve interactions with anime-styled pretty girls). Because of his famous abilities to "conquer" any 2D women in video games, he is referred to on the internet as "The God of Conquests." However, Keima is referred to as otamega, a disparaging combination of the terms "otaku" and "glasses," in his actual school life. Keima receives an email at the beginning of the series giving him a contract to "conquer" girls, and he accepts it under the impression that it is an invitation to a game challenge. In response, a Spirit Hunter by the name of Elsie, a charming demon from Hell, manifests. She solicits his assistance in order to help her track down the "Loose Souls," who were once Old Demons from Hell, who had escaped to the Human Realm. These demonic entities lurk inside the minds of young women, feeding on their hosts' bad feelings to regain their strength and power and reassemble into complete devils once more (and in turn, the host becomes an empty shell of a person). Elsie claims that the only way to get the evil spirits to leave is to "win" the girls' hearts by having them fall in love with him. By doing this, he would fill in the spaces where the evil spirits hide when they flee and she will be able to capture them. Keima, who is exclusively interested in video game girls, finds the idea repugnant and declines the task because he has never been in a love relationship in real life. However, since the contract has already been signed, Keima is obligated to assist Elsie since failing to do so will result in their beheading by a purple collar around their neck that is unseen to everyone else.