The white dragon of love. (high school dxd harem x OP male oc)

All Toad Skywalker ever wanted was a normal life. But it was anything but normal when his mother got remarried to a guy named Azazel who's the governor general of the fallen angels. And as a result he got 3 step sisters named Raynare, Kalawarner and Mittelte who has developed a secret crush on him. They told him that he had a sacred gear which is very powerful. His life got even more complicated when he met Rias Gremory who has not only taken in interest in him but also had fallen in love with him, among other girls.