Um Tae Woong has joined the cast of 'My Girlfriend Is an Agent'.

He will be playing the part of spy Choi Woo Hyuk, a genius industrial spy whose real name and face are not fully known. The actor joined the rest of the cast at the Thailand shooting recently to film the past of the charismatic Choi Woo Hyuk.

A representative said, "Um Tae Woong's joining of 'My Girlfriend Is an Agent' is a hidden card to ensure the rating for the first half of the drama. Please look forward to his endless battle with Joo Won."

Choi Woo Hyuk will be Um Tae Woong's first antagonistic role in 8 years. The actor has always played the main characters of highly popular shows and movies, such as 'Never Ending Story', 'Introduction to Architecture', 'Queen Seonduk', and 'Equator Man'. The staff revealed that Um Tae Woong took care of his hairstyle and clothes and completely left his 'innocent' image from '1 Night 2 Days' behind.

The drama will start airing in January.