When we meet Zhou Yi, she's about to embark on a long-promised trip with boyfriend Woody (Lawrence Chou), but a derailed conversation leads to a break-up - and it happens right in front of her ex-boyfriend Ping (William Chan) and his new girl Cee (Michelle Wai). With her passport in Woody's possession and some instant sympathy from Cee, Zhou Yi finds herself staying for a few days at Ping and Cee's pad.

Not smart - at least, not for Cee. With Zhou Yi hanging around, it becomes obvious that the two exes are not done with one another, their shared history bubbling to the surface with every recalled memory or sidelong glance that occurs over the ensuing days. Cee isn't as temperamental or impulsive as Zhou Yi - which likely makes her the better pick for a girlfriend - but Ping is instinctively drawn back to his ex.

For Zhou Yi, being near Ping brings back a wave of memories – flashbacks of not only her time with Ping, but with Woody, a triad fling (Jacky Heung) and even the fleeting moment where she may have drawn the attention of nice guy cab driver Sol (Derek Tsang). Will Zhou Yi get back together with Ping, or will the two grow or mature from this three-day test of inappropriate desire? Or maybe they'll just get it on for some quick-and-guilty sex-with-the-ex. Like life, there are myriad possibilities.

However, also like life, many of the people in Ex suck. Heiward Mak takes great care with her screenplay, creating real-seeming characters with believably complex emotions. But do we really want to know these people? Perhaps not, because we may know and be annoyed at people like them already. Ping and Zhou Yi are recognizable in that "Yeah, I know someone who's as selfish as they are" kind of way. Each cares for the other, but each also seems far more enamored of themselves.

That's not such a big deal for Ping, since the film is decidedly told from Zhou Yi's perspective - and if the ex-boyfriend is shown to be a self-serving screw-up, that's just fine. But, shouldn't Zhou Yi be someone who the audience, at the very end, sympathizes with? Shouldn't we wish for her to walk away from her exes, smarter and stronger for the experience? Audience survey says "yes", but Ex doesn't follow through.

The fault isn't Gillian Chung's. The actress embodies Zhou Yi perfectly well, her angelic features making her a picture-perfect object of adoration for the film's many weak-willed men. Zhou Yi is portrayed as an adorable and yet realistically self-involved girl whose emotional swings are as damaging to herself as others. Casting Chung is somewhat appropriate, as she too is well known for being much less perfect than her perfect features would indicate. The problem is that the film frames her in such a way that we should see beyond that definition - to find her a worthy person underneath the immaturity and self-involvement, and Chung doesn't have the depth to pull that off.

Hong Kong Cinema wunderkind Heiward Mak bites off way more than she can chew; her screenplay is rife with sharp observations and smart details, and she shows a real and deep understanding of Zhou Yi's difficult character. But sympathy for Zhou Yi never occurs. Zhou Yi is supposed to grow, but the decision that indicates her change is a tired and hackneyed metaphor rather than something strong or convincing. Even though the audience gets a good look inside Zhou Yi's head, she never becomes someone worth the adulation the onscreen males throw at her.

Realism could be one excuse for Zhou Yi's portrayal, but Ex isn't some dark exploration of relationships, nor is it a subversive look at how people mess with their significant others. Ex is smart and edgy but also earnest – a seductive pop-art concoction that bleeds supposedly winning style. Excellent cinematography and art direction dress up the film's many fine details and observations, and on superficial style alone, the film is enough to satisfy. The problem is beyond the excellent exterior is content that's much less attractive than the filmmakers would have you believe.

Heiward Mak has talent all right, and her work is exciting and confident enough that it's tempting to forgive its flaws on effort alone. However, Ex shouldn't get a pass because it can't compensate for its thematic or narrative deficiencies. Ex is surface entertainment that shouldn't be – a wannabe-telling relationship comedy that won't fool anyone with complete critical faculties. Still, even if it underwhelms, Ex looks like more than the work of a one-hit wonder. Heiward Mak will be back and she should be. Make no mistake, we will be watching. (Kozo, reviewed at the Hong Kong International Film Festival, 2010)

image credit: Emperor Motion Picture Group