The Japanese film industry was in decline at the start of the 1970s when Toho producer Fumio Tanaka proposed making a "Dracula for Japan". Hammer horror, basically. The director, Michio Yamamoto, though, preferred thrillers. They ended up with a compromise, with the story rewritten to include elements of both the horror Tanaka wanted and the thriller Yamamoto wanted.
The film ended up being the start of a "Bloodthirsty Trilogy", with the other two being Lake of Dracula and Evil of Dracula. (There are no plot links between them.) Those English titles are misleading, though, with this particular film containing no vampires and only a blink-and-you'll-miss-it doll. It is, though, reasonably okay. It's also very Hammer-ish, especially the sets, the mood and the unconvincing day-for-night shooting. (There are occasional shots with a European influence, though, e.g. the girlfriend flashback that looks a bit French-arty.) The film's playing with vampire imagery, but it's reluctant to embrace its own supernatural elements and only does so ultimately in an odd, Japanese way that makes it more of a ghost story.
I'll give the initial premise. A bloke called Sagara hasn't seen his girlfriend Yuuko in six months because he's been in America on for work, but now he's back. He goes to Yuuko's house (in the middle of nowhere, at night, during a thunderstorm), only to learn from her somewhat sinister mother that Yuuko was killed two weeks ago in a car accident.
To say any more would be a spoiler, but suffice to say that all is not well.
The house is old, creepy and self-consciously Western. Oil portraits, suits of armour, etc. It even has a sort-of hunchback. Technically, he isn't one, but he might as well be. His name's Genzo. He's mute, hostile and tends to attack people he doesn't like (i.e. everyone except Yuuko's mother).
Unlike 1970s Hammer, though, there's no nudity. (There is a floaty white nightdress, though, as was pretty much mandatory in Hammer's vampire films.)
The film isn't great, but it's okay. It might even improve on rewatching, since the backstory and character motivations are more solid than in most horror films and you'd probably find yourself getting more into that side of the film. You can definitely see the revenge/thriller elements. I'm not convinced that everything we're told is true (including certain details of the flashbacks), but there's nothing wrong with that. The people telling us this information aren't trustworthy. Is Genzo definitely a deaf-mute, for instance? Mute, yes. Deaf, unconvinced.
The atmosphere's also respectable. It's at least delicately sinister all the way through. Despite the pseudo-vampire imagery (no fangs, but a knife), I'd suggest approaching it like a ghost story.