He was one of the guests on an upcoming episode of MBC every1's 'Video Star', where he revealed he was originally supposed to debut with Seventeen. The two are in fact both from Pledis Entertainment.
However, when the MCs didn't believe him, he revealed, "I practiced songs with Seventeen. We went to dance together and the teacher told me never to dance again."
What do you think about a Seventeen with Han Dong Geun in it? The episode will air on the 19th.