Kuon

Kuon is a horror game set in Heian period (12th century) in Japan. You control three protagonists in the game. The story revolves around a man named Doman, an exorcist who was summoned by one of the noblemen to investigate a cursed manor. His daughter Utsuki is out to search for him when he doesn't return, and her sister is charmed by demons inhabiting a mysterious castle, turning into a demon herself.