The CEO of ZAIA headquarters, Leon Akland, intends to export the independent soldier Humagear "Solder" developed by ZAIA to countries all over the world, and use the collective brain system to control their intelligence so that they cannot reach the technological singularity. Leon transformed into Kamen Rider ZAIA using the driver that Asus gave him, and kidnapped Shun with two Solder soldiers. In order to rescue Horobi, Naki, Jin and Ikazuchi went to the Japanese branch of ZAIA. Under the stimulation of the collective brain system, they evolved into Kamen Rider METSUBOUJINNRAI, who did not know that all of this was actually in Leon's plan...