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 Won