After finding Philip trying to train like a boxer through weight-loss hell tactics in the RevolGarry's cockpit after listening to Wakana, seeing a tiny dinosaur robot from his past, the Narumi Detective Agency gets a new client named Fuyumi Aso who ask them to find a Kamen Rider. Thinking it was easy, they learn that the "Kamen Rider" is actually an impostor who has gone on a crime spree and Shotaro takes the case to get to the bottom of it after learning more at the site of culprit's robbery on an armored truck. Using the Bat Shot, Shotaro finds the culprit Dopant riding a motorcycle to attack the next armored truck and he arrives as Kamen Rider Double in time to stop the attack as the Arms Dopant flees from the scene.