It was the Taisho era... Amelie Haruzono, a cheerful and forward-looking girl with Western motherly features, attends an all-girls high school despite being subject to curious stares. However, one day, after a certain incident, Amelie begins to be attacked by yokai (monsters) as if drawn to her. She is saved by a mysterious military man named Akatsuki, but Akatsuki, driven by Amelie's blood, goes on a rampage. When Akatsuki, who is half yokai and half fox spirit, meets Amelie, he makes a "declaration" that she is already his bride...!? Why is Amelie being targeted by yokai? What is the secret organization "Domination" to which Akatsuki belongs? And what is the fate of the encounter between "the two"? A story that shakes the world of humans and yokai is about to begin!