In a recent interview with a media outlet in Hong Kong on April 6, Song Joong Ki talked about the cameo of his good friend Lee Kwang Soo in his drama, 'Descendants of the Sun.'

He was asked what was most memorable about Lee Kwang Soo's cameo, and he said, "We've always been close, so it was very comfortable filming.  He was unable to sleep at all because he came after filming 'Running Man' up to the night before the day of his [cameo] filming, but he really did his best.  He's my friend, but I was really touched and grateful."

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When asked about his thoughts on appearing as a guest on 'Running Man,' Song Joong Ki said, "I do want to appear [again] someday.  'Running Man' is a place that is like a hometown to me.  If I get the chance, I want to appear."

He also talked about how he felt regarding the composite pictures of Lee Kwang Soo's face put onto Song Hye Kyo's body.  "I was completely surprised," he said.  "From far away, I thought it was Song Hye Kyo, but when I looked closer, it was Kwang Soo.  Song Hye Kyo and Lee Kwang Soo look nothing alike, though.  If I look at it now, it's a good memory. Previously, Lee Kwang Soo sent a picture from Hong Kong, and I deleted it right away," causing laughter.