High School DxD

Issei Hyodo is a high school student who is unpopular with girls. One day, while studying at Kuoh Academy, he finds Rias Gremory, the crimson-red haired top idol of the academy, wondering who he is. While dreaming of having a girlfriend, another girl named Yuma Amano shyly asks Issei out to his excitement. After their first date, Yuma asks Issei if he will die for her. Revealing herself as Raynare, a fallen angel, she kills Issei by stabbing him in the abdomen. He sees a vision of Rias, but wakes up the next day intact, assuming the incident to be a dream. However, when Issei is stabbed in the abdomen again, this time by Dohnaseek, Rias intervenes, saying that Issei is her own. The next morning, Issei discovers he and Rias are naked together in bed. Reassuring that the dreams were real, Rias introduces herself as a devil and his new master.  (Source: Wikipedia)