Japan, our days. Ogi Takaya studies at a regular school in the provincial town of Matsumoto in Nagano Prefecture. One day, strange things begin to happen to his bosom friend, Narita Yuzuru, but Takaya has no idea how much these events will change his own life. He will have to come into contact with a world of ghosts, the existence of which he had not previously suspected, and plunge headlong into the most real war, which, as it turns out, has not stopped in Japan since the distant Middle Ages. It all starts with a chance meeting. Ogi Takaya meets with Naoe Nobutsuna, a mysterious young man who will tell him about the past.