Long ago, the Book of Ancients was the transcriber of history, recording everything known to man; myths, creatures, stories, science and technology, humanity evolved, civilization ... It was protected by the Sword of Logos, a sect of swordsmen tasked with protecting the book to keep the world in balance. However, thousands of years ago, the Megiddo attacked and tried to steal it. As a result, the Book vanished, and each of its pages scattered across the world. In the present day, young novelist Touma Kamiyama has been having dreams of another dimension, swordsmen and monsters coming out of a storybook, and a "mysterious girl" calling for help. Recalling the dream sends chills down his spine, not knowing anything about the dream. One day, a strange phenomenon occurred without notice; a part of the city disappeared, people's loved ones disappear one after another, and sends the entire nation into chaos. The vanished part of the city appeared in an alternate dimension, called Wonder World, an endless dimension as big as pages from a book. The dimension is home to magical creatures that attack without hesitation, sending the people in fear and confusion. As Touma and Mei are caught in this phenomenon, the attack reminds Touma of his dream as he is attacked by a mysterious monster. "I will definitely bring the city back to the original world!" As if it was responding to his very will, Touma harnesses the power of the red Dragon as it merges into his body, turning him into the Swordsman of Fire. The battle between the real world and Wonder World has an ending, and its destiny is in his hands.