When a group of a hundred members decides to create replicas of every single Rider belt from the 20 Heisei Riders, they launch a deadly battle royale called "The Sengoku Battle." With the help of Dai-Shocker, they distribute these belts to 20 random teenagers, telling them they will lead their factions and must fight other Rider factions. The winner is promised anything their heart desires. But in reality, the true goal is to watch Riders fight and kill each other for entertainment. Will the Riders uncover this sinister plan, or will they keep fighting to the death? Find out in the book!