This 2008 martial arts movie is from Thailand, and I enjoyed it quite a bit. We watched the English-dubbed version, which was fine; I'm no purist. Although some of the minor female characters were (I thought) pretty clearly being dubbed by males talking funny.
It's (initially) the story of two starcrossed lovers, Zin and Masashi. Zin is the ex-girlfriend of a mob boss, Masashi is in a rival gang, and the resulting betrayal-fueled carnage separates and exiles them under threat of death. But a child, Zen, also results. Zen is severely autistic, but happens to have unique talents: she absorbs vast martial arts skills simply by observing them, and she has near-supernatural senses and reflexes.
All well and good, but as Zen approaches her teen years, mother Zin gets cancer, requiring expensive treatment and medicine. Zen and her fat comic-relief cousin, Moom, decide to hit up Zin's former clients for the money they owe her. They react poorly, and Zen gets to use her unexpected martial talents quite a bit. Eventually, Masashi gets drawn back in, bad feelings are rekindled, and (as near as I can tell) nearly every Bangkok lowlife scum is called up to defeat the forces of decency.
Part of the fun is watching this little slip of a girl beat the heck out of a lot of unpleasant adversaries. The action is imaginatively choreographed; I found myself saying "whoa!" a lot. The violence escalates throughout the movie, leading to an impressive finale.