There's a simple hierarchy in the world; youkai exist to kill humans and hunters exist to kill youkai. As the daughter of a hunter Lilith knows this well, but she didn't expect her life to shatter at the revelation of a dark secret. She is a youkai. Now, with her life in ruins and facing execution, Lilith must abandon everything she knows. Under cover of darkness, Lilith flees to the port city, searching for a boat headed for Eden, the ringed city at the center of the world. There she hopes to start a new life for herself. But when she sells her spare ticket to a stoic woman named Pandora, she couldn't imagine she was inviting a hunter on the journey with her. Now, Lilith will have to hide her identity if she hopes to live. A task made more difficult when the two women grow closer and Lilith develops feelings for someone she can never be with.