Republic of Torchia began to decline with increasing poverty and dispute. In the past it was the Research Lab for Yggdrasill Corporation's Project Ark. Takatora Kureshima (Kamen Rider Zangetsu) who had finished his role of protecting the city gets to know that something strange is happening over there. He decides to step his foot in Republic of Torchia after 8 years. Because of an attack, he falls into the giant hole to the underground world called Underground City.
Underground City is one of the dangerous places in Republic of Torchia. Many youth over there used to kill each other to survive. There were also people who used to transform into Armored Rider using Sengoku Driver & Lock Seed. Takatora was injured due to the fall & he had lost his memory. He couldn't even remember his name. Takatora gets saved by Team Orange Ride's Leader Aimu. An Unknown Armored Rider suddenly appears. Aimu gets scared to the astounding power of this Armored Rider. Takatora remembers that this Armored Rider is Zangetsu.
Using the help of Aimu & others, Takatora makes the plan to call Armored Rider Zangetsu who the hint to bring back his memory. Meanwhile there was a man who was monitoring Takatora using the Cameras placed around the city. He wanted to take revenge on Takatora for some reason.
Team Orange Ride
Team Baroque Red
Team Green Dolls