Charlene Choi is magnificent as the schizophrenic, sad and lonely Winnie. Her face has a beauty suited to suppressed evil or desperate sadness inside, and she presents this facade so convincingly that in her very few, very brief moments of happiness, the shy and hopeful smile that accompanies the change evokes the poetic innocence of a rescued child. It's captivating and magnetic, drawing the viewer into a collaborative dream of promise that when quickly and sadly broken the feeling of empathy is profound. That's good acting and directing.
The ending very clearly presents a major twist. The cast credits only three people, so one must conclude that the real instigator was Winnie's neighbor, but it sure didn't look like the same person to me. Her character is presented as a likely ne'er do well but I'm not sure if it was her or if it was some alter ego, some schizophrenic other personality of Winnie. I think the ending twist is unnecessary and even though I didn't grasp the director's intent, it didn't bother me remotely enough to spoil the film.
Another aspect of the sensuousness of this film comes from the language and subtitles. This is a Hong Kong film, the language is Cantonese. I understand about three words of Cantonese but find the language wonderfully lyrical. Even in the few instances where the characters scream at one another there is a musicality to it. Most of the film drifts along like the melody of a bedtime lullaby, perhaps a byproduct of Charlene Choi's other profession as a (rather famous in Hong Kong) canto-pop singer.
Regarding the English subtitles—at least the set that accompanied the film I watched. Subtitles are a spongey issue. I imagine that one of two things are usually expected: that they are translationally accurate, or that they convey accurately the mood and intent of the speaker. One phrase uttered several times in this film by Winnie is, "I like to make puppets as I always think they are able to share with me". I don't know what that means because it could mean so many things. I hope the native language meaning is also as wonderfully ambiguous.
Anyone familiar with someone learning English as a second language has experienced moments of questionable grammar that are crystal clear in meaning and intent. I'm glad the subtitles appear to have been done by someone whose English is a second language. There are many examples, but a few gems for me were: "I like to make puppets and write my diary", "Do you have an affair?" (for, Are you having an affair?), "She instigated me!", and my favorite, "Seth often complained of my cookery." (You'll have to see the movie to enjoy the full impact of that last one.)
Diary is for the most part a dark, moody, mellow drama. But Oxide Pang throws in a little horror scene, a common practice in much of Asian cinema. I like to call it genre-hopping. I love the way he fuses a very sensual moment with fangs.