Kairu Nozokimasu is the protagonist of DxD: Battle of Dragon, he does manage to pick of a few girls but maintains positive relations with the others. Also known as the Grey Dragon Emperor, Kairu at first rivals the power hungry Issei Hyoudo, but with the battle at end friendship was not too far around the corner. Also no further relation was intended Kairu seemed to have stuck around with his counter parts. Thus introducing two new characters to the series