The Korean title "Yeopgijeogin geunyeo" can be translated into "That Bizarre Girl". And that should have been the English title cuz that's the main attraction. Like the old screwball comedies, its about the misadventures of a hapless guy who gets caught up with a tough, willful girl. At times he wants to avoid this badly behaving girl with a mysterious past, however pretty she is. That's sensible. She doesn't seem to like him. She constantly threatens him with "wanna die?" if he doesn't do what she expects him to do. And she punches him at will.
About the time the girl's parents are introduced, the story changes to a more conventional romance with more and more weepiness. And the ending, while clever, somehow reduces the effect of the earlier zaniness. It's almost as if the writer had a beginning for this crazy girl story but no ending. So he took a formula and twisted it a little to provide the final portion.
It still works cuz it remained largely unpredictable and the writing, direction and the hugely appealing actors (Jun Ji-hyun as the girl and Cha Tae-hyun as the guy) give it a homogeneity. Not surprisingly, this made Ji-hyun a star in Korea.
Overall, it's not perfect -- some facets aren't as polished as the rest -- but I'm gonna give it 5 stars anyway cuz the whole experience of the film haunts me still.
I'm a latecomer to Korean films. But that means to me that there are a number of precious gems like this one out there waiting for me to discover them.