Harutora Tsuchimikado was born into a famous onmyoji family but has no spirit sight, so he drifts through a rural branch school with his friend Touji Ato and expects nothing more of himself. That ends when Natsume Tsuchimikado, the clan heir and his childhood friend, comes back and holds him to an old promise to serve as her shikigami. The Onmyo Agency still polices what the Great Spiritual Disaster loosed, and the promise pulls Harutora straight into it.