The era is Taishō... Amelie Haruzono, a cheerful and bright girl with the looks of her Western mother, attends a prestigious all-girls school while enduring the stares and whispers of a society that sees her as different. But everything changes when she suddenly becomes the target of relentless attacks from youkai. Saved by a mysterious soldier named Akatsuki, Amelie soon learns that he too loses control under the influence of her blood. A half-youkai born of a fox spirit, Akatsuki mirrors the "otherness" Amelie feels within herself. Moved by this connection, Amelie makes a bold declaration to Akatsuki— Why is she being hunted by youkai? What is the secretive military group “Ha-Gun” that Akatsuki belongs to? When two outcasts meet, the boundary between humans and youkai begins to shake.