In'youchuu Shoku (2008)

The demon hunters are back! Mikoto, Sui, and Takeru are sent to investigate a mysterious island where people have been disappearing repeatedly and dark yoma are rumored to be the cause. When the team first arrives it almost feels like a vacation to them, but it doesn't take them long to the feel the presence of something dark and evil. (These OVA's are based on the game by Tinker Bell.)