Shigeru Daimonji, the Secretary of National Defense, has ordered Yua Yaiba/Kamen Rider Valkyrie to eliminate Kamen Rider MetsubouJinrai. While she hesitates to act on this directive, the Rider itself sets sights on Valkyrie. Meanwhile, the now former Solds attempt to discover freedom for the first time without ZAIA Enterprise, while engaging in an all-out war against A.I.M.S. Isamu Fuwa/Kamen Rider Vulcan, who personally witnessed the birth of Kamen Rider MetsubouJinrai, investigates to discover their true goal. What is Yua's fate, who acts on her own justice as she refuses to fight both Kamen Rider MetsubouJinrai, the Solds, and Isamu who is determined to carry out his final mission as Kamen Rider Vulcan?