Mao, a young mystic who lives in the Taisho period of early 1900s Japan,

is a mysterious onmyoji who, after suffering a life-altering curse, has continued to live for nine hundred long years. His world becomes even stranger when he meets Nanoka Kiba, a junior high schooler who seems to have traveled from the future. When Nanoka was young, she was involved in an accident with her parents, and she was the only one who survived.

But when Nanoka decides to return to that fateful shopping arcade where the accident happened, she is transported to another time and place—a world where supernatural ayakashi thrive in an era long before her own.

There she meets Mao, whose abrupt and bizarre question prompts Nanoka to see herself and her curious life in a completely new light.