During winter, a first grade high school boy, Rikudo Tokidoki, visits a traveling exhibition of “the Last Days of the Tokugawa Shogunate” held at an advanced museum using the latest technologies. It is a theme park where visitors can experience the last days of the Tokugawa Shogunate via computer graphics wearing special goggles.

However, when he is roaming around, Nue, a monster, appears and he is brought into the world “Amatsuki”. It looks like the last days of the Edo Era, but monsters and humans coexist there. He meets a girl, Kuchiha, who saves him from Nue, and classmate Shinonome Kon. Kon had also visited the exhibition but was transferred to a time two years prior to Tokidoki’s arrival. Together, they start looking for the way back to their world.

Later, after meeting Ginshu, a shrine maiden, and Bonten, a monster, Tokidoki learns of his fate.

Which path will Tokidoki choose? Will he become the destroyer of Amatsuki in order to go back, or will he become the ruler of “Amatsuki” in order to save it?