Japanese horror is a category of its own. It ranges from super-ridiculous B-movies (or is it C?) to cult classics. This one's neither, but it's certainly above average. It doesn't go into any extremes (like many Japanese horrors do) but instead focuses on characters and on making sense.The plot isn't very original, so it won't blow you away. Compared to most Japanese horrors, though, the story is coherent and well-paced, and acting is above average.The premise is simple. Harumi and Reiko start living together. After a while, Reiko starts having episodes of acting strange and referring to herself as Mari, which freaks Harumi out. Harumi's trying to figure out what's going on. There isn't much more I can say about the plot without spoilers.The movie overall isn't very scary. It's not something that will keep you on the edge of your chair. The horror element is certainly there, but most of the movie is more on the drama side. The pacing is slowish, but it didn't feel boring.More than half of the movie seems pretty straightforward and predictable. The plot twists come later. They're nothing too unusual either, but at least they make sense, and by the end of the movie, everything is explained well-enough to make for a decent story.All in all, the movie isn't mind-blowing, but it's well done.