Actor Park Ki Woong gave his insider's look on Kim Soo Hyun's real personality.

The two, who are co-stars on 'Secretly and Greatly', are pretty close, and Park Ki Woong decided to put Kim Soo Hyun on blast. Though many know the rising actor to be chic and charismatic, apparently, there's another side of Kim Soo Hyun.

On the July 8th broadcast of MBC FM's 'Younha's Starry Night', Park Ki Woong revealed, "I know Kim Soo Hyun's secret. It's not much, but his actual personality is a bit greedy and he has a one-track mind."

The radio host Younha then added, "I met Kim Soo Hyun at a movie press conference, and he sang my song in the way he wanted. He wasn't like his character on 'The Moon that Embraces the Sun' at all." Park Ki Woong agreed, "He's shy at first, but when you get to know him, he's a prankster and he has a one-track mind."

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