Mao claims to be over 900 years old by the 1920s, born sometime in the late Heian era. He grew up as an orphan, foraging in cave systems and learning to navigate by scent and sound alone. That harsh upbringing actually became his entry point—cave navigation served as a trial for admission to a school of onmyodo, a mystical practice blending early science with the supernatural. He passed the test handily, even saving a young Shiranui's life in the process, and by the late 1100s found himself formally trained and on a better path.
His skills never quite matched those of his peers, which made it all the more surprising when the school's master named him successor—especially when marriage to Sana, the master's daughter, came with promises of secret teachings and life-extension techniques. It was all a trap. Mao was meant to be a ritual sacrifice, someone expendable enough to dispose of for the greater good.
Everything fell apart when Byoki, a cat demon the school had created, broke loose and tore through the temple killing dozens. Mao killed it in combat but accidentally merged with Byoki's body in the process, absorbing its power. The head escaped, and Mao's memory goes blank. The survivors, though, had a different story: Mao had murdered Sana himself.
For nine centuries he carried that weight, living quietly as a doctor who treated both yokai and humans. Then came 1922 and the Great Kanto Earthquake, which thrust him back into battle with Byoki and dragged a modern girl named Nanoka into the past.
Content compiled by AnimeList.moe from publicly available sources.
