Book mode
Kamen Rider Decade's primary weapon. It was created alongside the Decadriver belt, as well as Kamen Rider Diend's Diendriver, by scientists of Dai Shocker, which included Yuuki Jouji.
It has three modes. The first, Book mode, is its basic mode, folding in half like a book, allowing you to remove Rider Cards from inside. It is usually attached to the left side of the Decadriver in this form. The second, Sword mode, is created by extending its blade and hilt to give it the shape of a sword. And the final, Gun mode, is the handgun-style configuration achieved by extending its barrel and grip.
