First on his social skills, Sungjae said, "I hide my real personality on first encounters but it might be in my nature to brighten when I hang out with people, because I get to know people really quickly. I'm comfortable around hyungs and noonas because I'm strangely always the maknae, but I have a hard time with same-age friends or younger generations." 

On the topic of his unchanging, young visuals, he stated, "The face that I've had since I was young is finally starting to act its age. I'm ignorant when it comes to facial care. When I was young, my mother and older sister took care of me all the time, like washing my face in rice water. But even now, I don't even put on lotion when I'm alone."

Sungjae also revealed that his dream job as a child was to be the owner of a PC cafe, and how proud he is to have been selected as Korea's endorsement model for 'Overwatch'. Finally, he named his favorite sunbae singer Kim Dong Ryul as the master he wants to visit on 'The Butlers'.