Shoko and Maiko Ougi are apparently two ordinary schoolgirls in pursuit of graduating and having fun. Shii-chan is the more serious while Mai-chan is more fun-loving. In reality, the two sisters are powerful exorcists from the Karura temple. Each wields half the power...Shii-chan can "see" the spirits, and Mai-chan can banish them. This is the movie adaptation of a spooky series with heavy emphasis on traditionally Japanese occult themes.

(Source: AnimeNfo's Karura Mau OVA description; modified)