After a blinding light emanates from her phone, soft-spoken Yuzuki is suddenly transported to an alternate world known as Shinga. The strange place resembles the Sengoku period—a turbulent time in Japanese history known for long civil wars that ravaged the country.

Here, the Gekkazoku, tribes of non-human creatures like vampires and werewolves, live in harmony with humans. This harmony was maintained under the governance of Himemiko, a woman with the power to protect Shinga. However, due to her mysterious disappearance, the world has fallen into disarray. Now, Yuzuki must find Himemiko in order to go back home; but, the ongoing feud between the warlords only impedes her progress.