Kanon is safe but the incident has not subsided. She is targeted by a secret enemy, and Rintaro moves in to fight them but the power of his Seiken is ineffective against the enemy. With both Rintaro and Kanon in danger, Makoto rushes in to save them. The Fukami siblings transform into Kamen Riders and launch a counterattack. Furthermore, Rintaro transforms into Kamen Rider Blades Specter Gekikou Senki form using the Specter Gekikou Senki Wonder Ride Book. The three Riders join forces to crush their evil enemies' plans!