Horrors of Malformed Men
So it's an erotically grotesque pink film that has been effectively banned in Japan because it disturbed people so much. This film is a nightmare in many ways: it contains sadism, murder, incest, transvestism, adultery, insanity, physical mutilation, physical deformity, dismemberment, suicide, human experimentation similar to that practiced in Nazi concentration camps by Joseph Mengele, and near-cannibalism (pulling off and eating animals that feast upon dead human flesh). It all starts as a mystery involving a man who suddenly finds himself in a mental institution with no idea why and ends with a series of shocking discovers on an island off the Japanese coast, with twists that at times could be from a Lovecraftian tale, which isn't that surprising, since Lovecraft was an enormous fan of Edgar Allan Poe, as was Edogawa Rampo, whose work served as the basis for this movie.
It's also a disturbing horror film...at least until supercop shows up and reveals the plot at the end through his uber detective skills. That deus ex machina ruins the day is the film's greatest flaw. Beyond that it is a disturbing and twisted nightmare of a movie that makes Hausu look like a Disney flick in comparison.