Door-Ju

The Door Gun (ドア銃) is a firearm weapon wielded by Kamen Rider Drive, resembling the driver-side door from Tridoron.

Arms Weapon
The Door Gun, alongside the Handle Sword, is the Arms Weapon wielded by either an Armored Rider or a New Generation Rider when they transform into Drive Arms, which is assumed by Kamen Rider Gaim in Kamen Rider × Kamen Rider Drive & Gaim: Movie War Full Throttle.