That was presented as an erotic polar/noir. Well first, it's really japanese to consider this erotic. There very single "erotic" scene (translate "where you can see a nipple") is of women being raped, gang raped, beaten and/or killed, fondled while unconscious (or dead, it's unclear), including by her father. In what seems like the potentially most consensual act, the guy still has a gun to her head.

Polar part is ok. A killer, Sho, is hired to get back his client's girlfriend and kill the ones responsible for her kidnapping. Turns out the main responsible, Ko is the one that killed the killer's own girlfriend a while ago.

It then gets pretty weird. Not as much as Branded to kill that apparently the director co wrote, but there are similarities. We see that Ko used to be Sho's close friend and he's been tracking him and fantasizing about killing him for years. They meet in a bar and have pretty gentlemanly conversation about killing each other.
A mysterious girl, that turns out to be Ko's girlfriend, ends up in Sho's hotel room. Conversations start getting weird and repetitive.

Twist: [spoiler]after killing everybody and getting the girl back, she won't wake up. While trying to wake her up, we realize that none of that happened, and all the recurring conversation bits were real words spoken in the hotel room where Sho was actually killed.[/spoiler]

The twist is nice, and not out of nowhere, the moment when things goes weird the first time is pretty noticeable, it just look like an old movie glitch so you don't pay too much attention to, it, that's all.

The action scene are a bit ridiculous (specially the very VERY exaggerated way people die).

The sex dolls in the title may relate to an ending scene where we see an hotel where what is presented as sex dolls in the room might actually be unconscious (or dead ?) girls. It's not quite sure how that relates to the rest of the story though.

In the end that's a nice polar with a weird structure and twist that could be used in modern movies, but not weird enough that it would be absurd. Not sure I got everything though, as the theatre had technical issues and we lost sound several times during the movie.