ouma and Mei find a girl who is looking for her brother. When they try to talk to her, she is attacked by Desast and runs away. Why is Desast after her? Touma and Mei chase after Desast to learn more. Meanwhile, as he’s looking for Kanon, Takeru finds survivors of Danton’s experiments and vows he won’t let them be sad like Chloe was. When he goes off to look for more survivors, he runs into Touma and Mei…

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!

After a long battle, a new Wonder World has been created! When Touma returns and everyone starts to relax, everyone begins to journey on their respective chosen paths! Mei spends some time with Rintaro as Touma spends some time with Kento at their secret hideout beneath the tree! It is there where Touma starts to tell Kento his thoughts... Just then, a young girl is suddenly attacked by a vicious creature, the likes of which no one has ever seen before! Hearing this was the place where three close friends met each other! However, those three friends won't be together for long, as this incident gives rise to a new kind of origin story! At long last, a new kind of encounter marks the beginning of a new kind of story...!