Thunder talked about going from a group to becoming a soloist on the December 15 airing of 'Kim Chang Ryul's Old School'!

He said, "I think [going solo] was a challenge for me.  The five of us [in MBLAQ] had parts that we were in charge of.  Honestly, I was not in charge of the music portion.  This time, I had to do everything on my own, so that was hard."

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Regarding whether he stays in touch with his former members, he said, "G.O and I often communicate.  [Lee Joon] came to visit me while I was practicing the choreography and he asked me to show him it.  But I felt shy, so I didn't show him and told him to just see it when it's on TV.  The members didn't contact me, so I personally contacted them first with, 'Please support me.'"