Traveling back in time, Saigyouji Hanyu finds himself in the Heian Period, a thousand years ago. The dog demons of the west are just beginning to rise, the raccoon cats of Shikoku are emerging, the flower demons of Izumo dominate the Tono region, and the Onmyoji of Heian-kyō aspire to overthrow both the Yin and Yang worlds... His father is the sorcerer who sealed the Saigyou demons, his sister is Saigyouji Yuyuko, he has a mentor, Kamo Tadayuki, and his senior is the Onmyoji Abe Haruaki. To seal the Saigyou demons, Saigyouji Hanyu, who originally wanted a simple life, embarks on the journey to become an Onmyoji, but his life gradually begins to fall apart... This is the story of an Onmyoji, his encounter with Gensokyo, and a young girl.