“Twee” is a seriously small target to aim for in a romantic comedy, a real “go twee or go home” gamble. And when you swing and miss? Ouchie.

“Love Type D” is an ever-so-slight, daft but deflatingly-so Britcom that never quite gets the job done. A little charm, a little bittersweet humor born of hurt, but writer-director Sascha Collington and star Mauve Dermody can’t find the sweet spot, can’t make this somewhat promising premise come off.

Dermody (“2:22”) is Frankie, an Aussie transplant muddling through her days as a cubicle drone in a London firm that produces instruction manuals. She’s never been that lucky at love, but in Thomas, a fellow she met a year ago, she thinks she’s found a winner.

Then he sends his much-younger stepbrother (Rory Stroud), a posh, polite little nerd always in his Blackfriars School uniform, to dump her. He gives her the “You’re a wonderful person” and “wasn’t really looking for a relationship” and “awfully busy” speech.

“What kind of grown man sends a ten year-old child…”

“Actually, I’m 11.”

Alas, love is illogical. He’s also the “kind of grown man” she cannot get out of her head. Phone messages and showing up at his apartment aren’t going to give her closure or satisfaction. Stalking little Wilbur when she spies him going into a jewelers gives her the answer. “Too busy,” “not looking for a relationship,” Thomas (Oliver Farnworth) has taken up with somebody else, an astronaut who happens to be “hotter.”

So he lied, two-timed her and sent his kid stepbrother as his break-up proxy. Why is Frankie still obsessed with him? It turns out she’s a tad too accustomed to this sort of rejection. It turns out that Wilbur, whom she hassles, confides in and consults, has some answers. There’s this research company that has discovered the “Type D” gene, the one that predicts whether you’ll be the “dumper” or the “dumpee” in life. Wilbur’s read up on it.

Frankie finagles a way to be tested, finagles a way for her fellow cubicle drones to be tested and discovered that most everybody she knows is destined for “a life of celibacy” and “hobbies.” But perhaps there’s a way to “cure” this. Of course, Wilbur has some theories.

That adorable set-up is the vehicle for a lot of lame flashbacks in which Frankie remembers every bloke who ever dumped her — the motorcycle “rebel,” the “musician” who wrote an “I could do better than you” song about her that went viral. Frankie needs to track these fellows down.

Schemes involving hypnosis and communing with the dead offer a chuckle here, a wince there.

A movie that structurally resembles Nick Hornby’s “High Fidelity” manages a cute moment or two, mainly in the scenes where a “grown woman” is taking advice — medical and personal — from a child. I laughed out loud once, and that required the distribution of elephant pheromones and Frankie’s attempt at being a sexy, sultry lounge singer.

The star’s likable enough. The germ of an idea is here. They’re aiming for the correct tone, but neither the script nor the players land on the “twee” bullseye.

MPA Rating: unrated, seriously PG, barely a hint of PG-13

Cast: Maeve Dermody, Rory Stroud and Oliver Farnworth

Credits: Scripted and directed by Sasha Collington. A Vertical release.

Running time: 1:35