Season 1

Keima is bishōjo gamer who is called "The Capturing God" on the Internet for his ability to capture any girl in any bishōjo game but does not like girls in real life. One day, he accidentally accepts a contract with the demoness Elsie to help her capture evil spirits that have escaped from hell and have hidden themselves in girls' hearts with the only way to force these spirits out is to make the girls fall in love with him. Keima angrily explains to Elsie that he doesn't like girls and his "capturing skills" only work in games but is shocked to learn that both of them will be killed by the magical collars on their necks if he breaks his contract, forcing him to comply. His first target is his classmate, Ayumi Takahara who is training for the upcoming track-and-field meet. Keima cheers her on by displaying banners using Elsie's magical raiment at the field everyday. While Ayumi is annoyed by his actions, Keima believes she will eventually get used to him and like him. After a confrontation with jealous seniors, Ayumi sprains her leg a day before the meet. However, Keima confronts her that night as he figured out that Ayumi faked her injury because her meeting with the seniors made her question her confidence. Keima consoles Ayumi and tells her to believe in herself, which makes her fall for Keima. They kiss when Ayumi keeps Keima from falling down the stairs, forcing the spirit out of her body and allowing Elsie to capture it. Ayumi wins the meet but loses all of her memories with Keima, though she blushes when Keima congratulates her. Much to his confusion, Elsie has transferred to his school, claiming to be his sister.

Keima confronts Elsie on why she’s still here and he still has the magic collar on his neck which the latter reveals that their contract is still not finish and the collar will only be removed until they capture all of the runaway spirits in the city. After meeting Keima’s mother, Mari, Elsie claims she is her “husband’s illegitimate child” which Mari snaps on her husband on the phone for his “infidelity” and allows Elsie to stay with them. Keima however, refuses to accept Elsie as his little sister as in his view, she doesn’t have the requirements that qualify her to be one which she tries to impress him albeit unsuccessfully. But upon hearing her story on wanting to be successful just like her older sister, Keima reluctantly accepts Elsie as his sister. During lunch at a popular food stall, Keima and Elsie find their next target, Mio Aoyama, a rich girl who proceeds to buy all of the yakisoba sandwiches. Keima believes she is an easy target as she has all the characteristics of a Tsundere, and a love confession might break her hard shell. However, the confession doesn’t work as planned, and Mio has her chauffeur beat Keima badly. As Keima and Elsie follow Mio to her home, they are surprised to learn Mio lives in a shabby apartment.