Girl's Day's Hyeri flattered her fellow cast member Yoo Seung Ho during an interview with 'Cosmopolitan' magazine. 

On December 21, Cosmopolitan Korea posted a video with the two main cast members of the upcoming drama 'When Flowers Bloom, I Think of the Moon.' On this day, the two answered questions about each other to gauge their chemistry with each other and to see how much they know about each other.

During the interview, Hyeri answered a few questions about Yoo Seung Ho that even the actor didn't expect her to know. He became flattered as he was impressed that Hyeri knew some of the questions.

In particular, when Yoo Seung Ho asked Hyeri which division of the military he was enlisted in, Hyeri answered with the correct answer right away. She replied, "you were part of the 'LET'S WIN' division (the 27th infantry division)." In response, Yoo Seung Ho exclaimed, "How did you know?"  Hyeri replied to Yoo Seung Ho, saying, "Of course I know, you were a recruit trainer."

However, Yoo Seung Ho was not able to properly answer some of the questions about Hyeri. In particular, when Hyeri asked where they first met, Yoo Seung Ho was not able to recall the moment making everyone laugh.