High School DxD, Vol. 1 - manga

When unpopular high schooler Issei Hyoudou ilas a less than romantic encounter with his first-ever girlfriend, the consequences are fatal! As he lies dying, who should come to his rescue but the prettiest girl in school, Rias Gremory! And the shocking truth she shares leaves Issei reeling... 'You've been reborn a devil. Now you work for me!' Issei's uproarious life as a devil's minion begins here!