For his first solo album, Dara made a special appearance in the MV for one of his new tracks, "Sign". When asked why she didn't feature in the song instead, Thunder revealed, "I do want to collaborate with her someday."
However, Thunder explained, "She looks after me because I'm the maknae but I believe work and family are two separate things. When I come home I don't want to talk about work, and for some reason, I tend to not do well when family members come to my concerts or filming sets. It just gets on my mind for some reason."
Hopefully we'll get to see a Thunder x Dara collaboration someday!