High school student Issei Hyoudou is your typical pervert who wastes his life on unproductive activities, such as peeping on women and dreaming of one day having his own harem. Issei’s prospects seem to improve when a beautiful girl asks him out on a date, but she turns out to be a fallen angel who brutally kills him! However, he gets a second chance at life when Rias Gremory, a beautiful senior student and top-class devil, revives him as her servant, recruiting Issei into the ranks of the school's Occult Research club. Slowly adjusting to his new life, Issei must train and fight in order to survive in the violent world of angels and devils. Each new adventure leads to many hilarious (and risqué) moments with his new comrades, all the while keeping his new life a secret from his friends and family in High School DxD!