He is hired by Saeko to lure Philip out of hiding. Given the Arms Memory, it turns Kurata into an uncontrollable sadist as he turns his back on Fuyumi and the morals they followed. The Arms Dopant goes on a burglary spree and claims to be a Kamen Rider to force Double into the trap, only able to capture Shotaro and Akiko to use as hostages. However, the unexpected return of Kamen Rider W FangJoker, and eventual control of the form, turns the tables with the Fang Streiser Maximum Drive as the defeated Kurata is left for the police.
The Arms Dopant is able to morph his left forearm into a variety weapons such as a gun and carries around a giant blade-like weapon called the Shield Sword. The Arms Dopant has his own personal Honda Valkyrie motorcycle called the Arms Bike.