With leftover surgery equipment, the Double Riders transform Shirou into the powerful third Rider, Masked Rider V3! However, the Double Riders sacrifice their lives to save Tokyo from another Destron monster, Turtle-Bazooka, who had an atomic bomb hidden in his body! Kazami had to use his powers to fight Destron without the guidance of the Double Riders. Young girl Junko Tama also gets involved, and after Shirou took her to his family's house for safety, Destron monster Scissors-Jaguar stumbles onto her and before Shirou's eyes, kills his whole family (his father, mother, and younger sister)! But before Shirou and Junko were about to be killed as well, Shirou's friend Takeshi Hongou, alias Masked Rider 1, comes to the rescue! An enraged Shirou wants to be a Masked Rider just like him and Hayato Ichimonji (Rider 2), but the Double Riders won't allow it (they don't want another cyborg burdened by the loss of humanity), until, that is, Shirou sacrifices his own life to save them from a trap set by the mysterious Leader of Destron in the remains of Gelshocker's old base.

Athlete/motorcycle daredevil Shirou Kazami was a witness to the doings of the evil Destron (an offshoot of the first Shocker/Gelshocker society from the first show), which subsequently sought to kill him.

Kamen rider kuuga helmet