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!
Esta é uma adaptação para o cinema de Kamen Rider 555, que é considerada uma continuação de um final alternativo da série em que os Orphenochs venceram a batalha contra os humanos e dominaram o mundo. Os humanos ficam recuados devido a suposta morte de Takumi. Mari, que era muito ligada a ele, não se conforma, pois Takumi desapareceu bem diante seus olhos. A resistência humana, liderada por Mari, monta um ataque a Smart Brain, que fracassa. Masato, o Kamen Rider Kaiza, é a única esperança dos humanos, mas ele só luta por seus próprios interesses e em troca de favores. Com o surgimento de Psyga, Kaixa é morto, mas os humanos ainda contam com a ajuda dos três Orphenochs rebeldes. Takumi é encontrado com amnesia e vivendo uma nova vida. Ele volta mais tarde para salvar o dia.
