What a peculiar, sometimes bizarre movie “Homunculus” is, a brain-experiment sci-fi thriller that lurches between dull and downright revolting.starts with graphic brain surgery, crosses into “creepy,” and freely-acknowledges that when it does, as it dabbles in the Japanese obsession with uniformed “schoolgirls,” and goes gonzo gross, before settling into sheer tedium.

This Around the World with Netflix thriller starts with graphic brain surgery, crosses into “creepy,” and freely-acknowledges that when it does, as it dabbles in the Japanese obsession with uniformed “schoolgirls,” and goes gonzo gross, before settling into sheer tedium.

It’s about a homeless guy (Gô Ayano) who lives in his ’60s Mazda, occasionally socializes with the homeless encamped in a nearby park and gorges on big swathes of the menu when he deigns to go out.

He’s got money, everybody says. But he’s living like this. He must have his reasons.

They don’t become crystal clear when he’s approached by a pierced, pushy street punk (Ryô Narita) who turns out to be a “rich kid doctor.” He wants to do a little ancient brain surgery on Nokoshi, and eventually gets to the heart of his pitch.

“Do you ever feel alive?”

Nokoshi ignores the dangers of the most invasive of surgeries, the dubious credentials of his pitchman and Ito willingness to resort to extortion, and agrees to the surgery.

Maybe he’ll “remember what you forgot” after this trepanation — trepanning, boring a hole in the skull (seen in “Master & Commander”). Maybe he’ll discover a sixth sense. There are all sorts of possibilities when you pop the bone off the lid of your noggin.

“ESP, psychokinesis,” Ito teases, dubbed into English or in Japanese with English subtitles. “Give me seven days and I’ll give you a reason to live!”

What he actually gives Nokoshi, aside from a big band-aid covering the hole in his forehead and the recovery of “memories,” is the ability to see people as “homunculi,” beasts as they really are. Some are made of sand, others of water. They can be walking chains or “empty” creatures covered in sunglasses.

Nokoshi knows the yakuza whom he confuses for a robot has a gigantic emotional scar he’s based his life on. His threat of violence can be turned on his by twisting his mind.

This school girl (Seiyô Uchino) who moonlights in a peep show (the school uniform fetish) has hang-ups that come off as pervy older man wish-fulfillment fantasies. I’m not overstating it in saying this borders on nauseating.

The performances never quite achieve “compelling.”

And the action of the first half of Takashi Shimzu’s film — based on a manga, of course — is abandoned for far duller later scenes and acts, less sick or sickening, but not thought-provoking enough to hold interest.

That’s how the film leaves you, with a wincing realization that “That’s it?”

MPA Rating: TV-MA, violence, sexual violence, sexuality and profanity

Cast: Gô Ayano, Ryô Narita

Credits: Directed by Takashi Shimizu, script by Eisuke Naitô, Naruki Matsuhisa and Takashi Shimizu, based on the manga by Hideo Yamamoto. A Netflix release.

Running time: 1:55