Based on

Movies like Kamen Rider Ryuki Special: 13 Riders (2002)

This television special is an alternate telling of the Kamen Rider Ryuki story. Shinji Kido's life, working as an employee at ORE Journal, takes a sharp turn after being pulled into the Mirror World by a Mispider. Luckily, he was saved by Kamen Rider Ryuki, Koichi Sakakibara. However, Sakakibara could no longer go on due to the severity of his injuries and passed his Card Deck to Shinji, allowing him to become the next Ryuki and defeat the monster.