Kamen Rider OOO (小説 仮面ライダーオーズ Shōsetsu Kamen Raidā Ōzu), written by Nobuhiro Mori, is part of a series of spin-off novel adaptations of the Heisei Era Kamen Riders. The novel is split in three parts. 1. * The first part, Ankh's part, focuses on the origin of the Core Medals, the King, and the Greeeds from Ankh's point of view and reveal secrets unanswered from the series. 2. * The second part, Birth's part, focuses on a bored Akira Date writing a short story on the Birth Driver's point of view, deciding between Akira Date and Shintaro Goto to see who is worthy to use it. 3. * The final part, Eiji's part, focuses on Eiji's past and reveals how he met the girl who died during a war.