Lee Sang Yup says he was caught offguard by Lee Min Jung's unscripted smack.

At the March 24th press conference for the upcoming KBS drama 'Once Again', Lee Sang Yup talked about his co-star, saying, "She's very carefree and easy to talk with, so I feel comfortable with her. I'm not sure how Lee Min Jung herself feels." The actress responded, "I feel very comfortable. He has a very good personality. I'm filming in a delightful atmosphere."

Lee Min Jung also shared, "There was a scene where he throws something at me and pushes me, and my hand suddenly smacked him in the back." Lee Sang Yup then expressed, "There are a lot of scenes of me caught offguard because of smack on the back that wasn't in the script."

'Once Again' premieres on March 28 at 7:55PM KST.