Ashiya Michitomo, the legendary onmyoji hailed as the mightiest of the Heian era, is betrayed by his close friend and rival, Abe Seimei. This treachery leads to the massacre of Michitomo's entire clan. On the verge of death, Michitomo activates a forbidden reincarnation spell, awakening centuries later in the modern world.

This new era is one where yokai run rampant, and exorcists are revered as heroes for purging these supernatural threats. However, Michitomo discovers that the legacy of his Ashiya clan has been twisted beyond recognition. Once respected, the Ashiya name has fallen into disgrace, labeled as a clan of traitors who betrayed the Abe clan and suffered a devastating defeat. While the Abe clan has risen to become a powerful and dominant force in the modern world of exorcists, the Ashiya clan remains in ruin, suffering from oppression and contempt due to Michitomo's own past defeat.

Upon learning of his clan's suffering, Michitomo vows to revive the Ashiya clan to its former glory and exact brutal revenge against the Abe clan who wronged him. From childhood in his new life, he devotes himself to rigorous training, aiming to reawaken as the strongest onmyoji of the modern age. With the mightiest yokai by his side, beings who pledge unwavering loyalty to him as his shikigami, Michitomo embarks on a path of unrivaled dominance in the world of exorcists. His journey is one of restoring honor to his bloodline while dismantling the powerful clan that destroyed his first life.