The film "Twenty" gave actress Lee Yu Bi the opportunity to film a seduction scene and to improvise on the script's directions.

In "Twenty" her character So Hee has a crush on Dong Woo, played by 2PM's Junho. Dong Woo is close to her character's older brother played by Kang Ha Neul. So Hee has known Dong Woo for years but never had a chance to express her feelings. Then one day she is a substitute model at the art school where he takes classes. It's her opportunity to make an impression, so the actress added a little something extra by flirtatiously lifting up her skirt.

"The scene where I stand in as a model at an art school and lift my skirt slightly for Dong Woo was adlibbed," said Lee in an interview with Newsen. "I was thinking how to express So Hee's affection for Dong Woo in a light, yet cute way and that was the result."

The director liked her ad-libbed touch to the scene and kept it in the film.

It's fitting that she attempts to seduce him in an art class. So Hee's crush Dong Woo dreams of being an artist but after his family goes bankrupt he has to take several part time jobs to help out. Still, his family's bad luck does not diminish So Hee's feelings for him.

"I think that So Hee liked Dong Woo since she was young. She's a brave girl who, after some time passes, mustered up the courage to approach him first," said Lee Yu Bi, who was last seen in the dramas "Pinocchio" and "Gu Family Book," and also in the film "The Royal Tailor."

But bravely approaching a crush might not be Lee Yu Bi's reaction in real life.

"I'm not the type of person who can approach someone straightforwardly first," she said. "If Dong Woo existed in real life, I don't think he would have found my timidity charming."

But that's okay because Junho said in a recent Newsen interview that he would never date a friend's younger sister.

"If it was me, I couldn't do it," he said. "Even if we somehow ended up dating, I would do it in secret. If it was revealed, I could lose both my friend and my girlfriend."

He won't even introduce his friends to his real-life older sister.

So far the film has done really well at the box office. According to the Korean Film Council, the film attracted 200 million moviegoers in the first 12 days.