While in Zawame City’s Free Performance Zone, Mai and Mitsuzane of the Team Gaim are having a free-spirited dance when members of rival Team Baron scare them away when an Inves Game gets out of hand. When Mai goes to former teammate Kazuraba Kouta to reveal something strange has happened, he reveals that Team Gaim’s leader Yuuya gave him a strange Lockseed, and Mai reveals Yuuya informed her of it as well. The two eventually find a way into the Helheim Forest and discover a strange belt…
整座遭異世界怪物騷擾不寧的澤芽市，假面騎士展開了如火如荼的鬥爭。 這不僅是為了守護鎮上居民，也是為了貫徹自己心中的正義而戰……。 讓他們多次出入戰場的意志究竟是什麼？在他們達到目標後又能獲得什麼呢？假面騎士戰國時代，就此開戰！
