Synopsis:
At the start of the series, Keima receives an e-mail offering him a contract to "conquer" girls. When he accepts it, thinking it is an invitation to a game, a demon from Hell named Elsie appears. She asks for his cooperation to help her in catching runaway spirits. These spirits hide themselves inside the hearts of girls, and Elsie suggests that the only method to force the spirits out is by "conquering" the girl’s hearts, making them fall in love with him and filling up the gaps which the runaway spirits hide in. Interested only in 2D girls, however, Keima is appalled by the idea, and refuses the assignment as he has no romantic real life experiences whatsoever.
