Are�SECRET's Sunhwa and actor�Jin Goo on their way to becoming 'national siblings'?

'Advertisement Genius Lee Tae Baek' released still cuts of the pair posing happily with each other. Jin Goo plays the main character Lee Tae Baek, who needs to support himself, his grandmother, and his little sister. Played by Sunhwa, his younger sister might come off as thoughtless and hyper at first, but she actually cares very much about the well-being of her family.

When Sunhwa's character said she wanted to quit school because it was too expensive, Lee Tae Baek balked and said he'd get her tuition no matter what. When a guy tried to flirt with her during her part-time job, he came up immediately as the protective older brother. The photos revealed seem to prove that they're close off-screen as well.

Viewers commented, "When they're on, I can't help but smile," "They remind me of me and my brother," "Tae Baek loves his dongseng," and more.

Have you been watching the drama?