Hollywood actress YUNJIN KIM finds her part in hit show Lost a challenge - because she's used to playing the exact opposite of her character SUN. Kim, who rose to fame in Korea playing a powerful female assassin in hit movie SHIRI, had always played strong, willful females before Lost. And the martial arts star finds it very difficult to act meek housewife Sun. She says, "In Shiri it was a powerful La Femme Nikita type of role - a female sniper. "I went as far as a brown-tipped belt in tae kwon do, but each school is very different as far as status of belts and colours is concerned, so it's hard to explain what level I was at. "I'd already had dance training which meant I was flexible and good at remembering choreography, so I learned fast. I also did broadsword fighting and combat with a shorter sword."