On September 26, SBS'�'Secret Door' released behind-the-scenes pictures of Kim Yoo Jung stretching before filming. The scene she is preparing for seems to be one in which her reckless, mysterious character Seo Ji Dam has to run away from the authorities.

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Both her flexibility and her determination shine through in the photos, and her stoic expressions especially amused netizens, who left comments like, "How hard is she planning to run keke, look at her expression. She's stretching with such determination. So cute!"

In other news, 'Secret Door' just made its premiere earlier this week and is currently competing with MBC's 'The Night's Watchman' for the top spot in ratings.�