Ghost Slayers Ayashi Episode 1: The Youi Arrival
Episode 1 of 25 of Ghost Slayers Ayashi, aired October 7, 2006, 25 minutes. Available with English subtitles and dub where released.
Episode summary
Edo, Tenpo Year 14. The Ayashi of the Office of Barbarian Knowledge Enforcement secretly investigate the existence of a Youi. Yukiatsu Ryudo encounters a mother and son and gives them refuge, but the Other World appears and a giant Youi comes forth. Source: crunchyroll