Set in 16th Century Japan, the film takes place against a background of civil war, with the Iga ninja being ruled over by warlord Nobunaga Oda with an iron fist, keeping them in check with harsh laws and handing out executions at will. Mika Hijii plays Ukagami, the toughest female warrior of her clan, who is sent out on a mission by the villainous ‘Lesser Ninja’ as part of his plot to take over the Iga. After his trap fails, he kidnaps her childhood friend, pushing her to go against the clan in a bloody mission of rescue and revenge.
Yu confronts a number of events and encounters: Reunion with a high school classmates, a close friend who suffers from serious illness and a former lover, among others.By feeling the severity of the flow of time, Yu will know one truth of "Life".
The story begins with a regular day with Takumi, Mari and Keitaro, which suddenly turns into a musical number thanks to a mysterious new boom box created by Smart Brain. As it turns out, Yuji, Yuka and Naoya have the same boom box and are greeted by a rapping Smart Lady who reveals that it's part of a new plan by Smart Brain to invoke people into singing all over Japan. The reason: To get the three Rider Belts back!
In the near future, the world is ruled by the Smart Brain Corporation, with 90% of the population being Orphnoch, and the once prominent human race is nearing extinction. Takumi Inui, Kamen Rider Faiz, was once regarded as mankind’s savior until, in an attack by Smart Brain troops, he was presumed dead. Since then, human rebel groups have staged attacks on Smart Brain’s complex in an attempt to steal the top-secret Emperor Belts, with no success. Kiba Yuji, Naoya Kaidō and Yuka Osada attempt to ease tensions between both races but their peace meeting is interrupted by Smart Brain troops and their newest warrior, Kamen Rider Psyga. Takumi, believing himself a young cobbler named Takeshi, regains his memory and becomes Kamen Rider Faiz again to settle things with Smart Brain once and for all.
