To you It will seem strange. The film has just begun and you are watching zany scenes. But it's a "Guinea Pig"!. All correct, no error, it's the final twist of the series that ends here its crazy saga. There would be a "making of" and a "best of" but are part of another story.
Be careful, while you watching this sixth chapter and don't relax too much, (as we did we admit it ...) and think that this is a little easy and funny movie, because the strong scene nauseating, disgusting and bloody, are there, shortly after, waiting for you.
"Devil Woman Doctor" is a kind of parade of freaks led by a doctor played by a transvestite well known in Japan, Shinnosuke Hikeata, also called Peter. She is the doctor who likes to take care of these patients but also eliminate eccentric.
Various sketches form the chapters of the film and in each there is a case report. A nice list with an angry family to which his head explodes, a girl faint of heart, a zombie husband, a buffet of human organs, a human organ that chases a girl on the subway, four patients who are told their illness and an incredible tattoo to be removed.
Playing on the fact that they are all lame, sick or insane are allowed to exaggerate, allowed to cross the border without being vulgar or inappropriate. Blood, decomposition, mutilation, and scalps, and more in a comic noir/horror style very funny.  
The result is not bad, indeed, some scenes are really funny, like the buffet of zombie bodies or husband or even the four patients.
Smart then the end with a typical slapstick scene that lightens the whole context, revealing part of the game and took leave with a sense of peace from the whole series.