I realized that Yoochun is fan of Kim Don Ryul who is also famous and talented Korean singer.
Because, Yoochun always selects his hit songs to cover for concerts. He sang “Drunken Truth" at JYJ Worldwilde Concert in Seoul. And now He sang "Old Song" in Tokyo Dome. I think, the songs souit him very well. I hope that Park Yoochun and Kim Don Ryul could a duet in future. I love two of them.