Ko Sung Hee will play Kim Jaejoong's lover in the upcoming drama "The Spy."

In the upcoming drama JYJ's Kim Jaejoong plays Sun Woo. His character is a genius that works as an analyst at the National Intelligence Service. Sun Woo is calm and collected. He analyzes things carefully, sifting through the fine print to find out what's true and what's not. He is a stickler for details, since his and the nation's decisions often depend on them. But he is not as fussy once he leaves the office. He's warm and caring to those he knows and loves.

Kim Jaejoong said he was drawn to the role because of the storyline and the charming character.

Ko Sung Hee will play his romantic interest. She plays Yoon Jin, a mysterious company worker with a secret.

"I'm excited for my first project with KBS," said Ko Sung Hee. "Since Yoon Jin is a secretive woman in the drama, I will do my best to make the viewers more curious as they watch."

Her comments also provided a clue into what viewers can expect from her character. It sounds like Yoon Jin may not always do the right thing but she has her reasons.

"I hope that you can embrace Yoon Jin, who has a painful heart, and see her in a positive light," she said.

"Spy" is a remake of an Israeli drama. It tells the story of a mother who seems to live a normal life as a housewife but then her son finds out about her life as a spy.

"Based on the original piece called "Mice," which has already received recognition overseas, it is fast-paced and deals with interesting subjects," said Jaejoong. "So it will be a project worth watching for those who favor foreign dramas. I will do my best to show my good side."

Singer-turned-actor Kim Jaejoong has been showing much of his good side in recent dramas. He appeared in "Dr. Jin" and "Protect the Boss" and then impressed viewers with his ever-improving acting skills in the melodrama "Triangle." In that drama he played a man who transforms from a self-defeating loser to a confident self-made man.

Relative newcomer Ko Sung Hee recently appeared in the MBS fantasy drama "Diary of the Night Watchman," as well as the drama "Miss Korea." She had roles in the films "Fasten Your Seatbelt" and "An Ethics Lesson."

The drama series will air two 50-minute episodes every Friday night.