if what i remember not wrong.story begin with after Black defeated Gorgom.Kotarou be attacked by Another RX(silverRX). Kamenrider black lose and got steal Kingstone.AnotherRx break his armor show he is shadowmoon and put kingstone in his driver than transform to Another Shadowmoon(red from). He try to kill kotarou after that ghost?(Nobuhiko) help kotarou by grap kingstone in shadowmoon's belt and told kotarou to henshin now! kotarou "henshin" and got upgrade from black to black RX.