Lee Haeri of the group Da Vici has mentioned Junsu in an interview. We’ve translated the relevant excerpt:
Question: Lee Haeri partnered with JYJ’s Kim Junsu in a musical.
Lee Haeri: He is Asia’s star. But he has a side that is very innocent and childlike. He also has an appeal that is unlike a star. He is very good at singing and since he has done a musical before he also had more experience that I did. He was a great partner.