Abe no Seimei was the supreme onmyoji of mid-Heian Japan, trusted by Emperor Ichijo and Fujiwara no Michinaga as the highest authority in astronomical divination. He lived to 85 and was a genuine astronomer and calendar scholar. Legends — commanding shikigami spirits, seeing demons, winning sorcery duels — grew through later tales and Edo-period fiction. Today he is a superstar of Japanese pop culture, appearing in novels, films, and games.