The common knock against science fiction writer Greg Egan is that, for all the fascination inherent in his scenarios, he is unable to create characters. I've always found this claim to be unfair - it's not that he doesn't create characters, it's just that those characters are always first and foremost a function of the scenario. The only part of their history, of their personality, that we get to see is the part that has a direct bearing on the philosophical question at hand. They're highly detailed people; they're just very narrowly detailed people.
I don't think there's anything wrong with this approach. There might be if Egan were attempting character studies but he's not. He's interested in exploring the personal and philosophical conundrums that rapidly changing technology presents. To my mind that's as valid a mission for an artist as creating complex personal portraits is.
It's a mission that, on the basis of Time anyway, Kim Ki-duk shares. To be fair Ki-duk isn't really interested in the possibilities and pitfalls of plastic surgery and what they might mean for us on a realistic level, but he does seem interested in very narrow philosophical questions of intimacy, novelty and identity and his character's traits are subordinated to exploring those questions.
Time is about the desire to enjoy intimacy with one person "till death do us part" and yet also the need to constantly be surprised and excited by that person. To maintain her lover's (Ji-Woo) interest the female protagonist (Seh-Hee) undergoes plastic surgery to make her self unrecognisable and enters his life again as a new person.