With their tour of the nine Kamen Rider Worlds complete, the Hikari Studio group returns to their home world, finding it as it was before the monsters appeared. Tsukasa is the only one who feels something is not right and questions the reason for the journey. Before Yusuke or Natsumi can attempt to answer, they encounter the violinist Otoya Kurenai, who thanks them for saving the world and tells Tsukasa that he earned a world of his own for his journey. As Natsumi goes out to see her TG Club friends and teacher for a high school reunion, Tsukasa and Yusuke have a short encounter with Narutaki who congratulates him on getting his own world. Later, Tsukasa becomes the ten-thousandth customer in a restaurant and wins both a free meal as well as a vast fortune. Tsukasa enjoys the upper class lifestyle until he takes his leave during an arranged marriage meeting. Yusuke is forced to take his place, but he runs off upon realizing that the women are actually monsters in disguise. Elsewhere, while hanging out with her TG Club friends, Natsumi tries to figure out where her friend Chinatsu is, and the TG Club members take the opportunity to run off, with the teacher attacking a couple as Alternative. Tsukasa runs into Otoya who mentions a treasure before transforming into Dark Kiva and challenging him, along with the other members of the TG Club who become Ryuga, Dark Kabuto, and Orga. With Diend arriving to back him up for this treasure, Decade battles Dark Kiva. When Decade attempts to use his Final Attack Ride against Dark Kiva, the attack suddently cancels as he falls and reverts back to human. As the dark Riders leave, Tsukasa realizes that all of his Rider cards have turned black. Elsewhere, Natsumi is still searching for Chinatsu when she passes by someone in dirty and ragged clothing who turns out to be another Natsumi.[20]
