I think this is a movie with 誠意.  First, take a look at the name of the movie: 天生一對.  It mentions something in pair.  Then, the English name:  "Two become one" which is also talking about the theme of the story.

The movie is very positive.  The Yeung knows that she has breast cancer at the very beginning, she faces it with courage.  She only thinks "she is unlucky".  Hey~!  in the middle of the movie she commits suicide only because of the betrayal of her ex, the work ... but Richie Ren and the Wong Man Wai enlighten her.  Wong said:  Charcoal is highly dangerous goods and the price would not increase.  Please make sure you get it only when you need it.  See ... it's so humurous ... Safe life.  Don't kill yourself.

Richie Ren also brings out positive thoughts to girls.  A man who really loves you would not mind you only have 1 breast.  Girls, take this message serious.  The man who get laid with you is not necessarily the one who loves you.  Be careful~

This is the part I like - when Yeung is on the operation table at the end of the movie, she thanks her left breast for accompanying her and will remember her.  So sweet ... she doesn't blame it for bringing the cancer to her.  After all, you body is always your best friend. 

The movie is not a really great one, but I like the message behind - BE POSITIVE.