On the April 29 edition of SBS radio program 'Kim Chan Ryul's Old School,' 15& discussed their school and social lives.

Park Ji Min said, "At school, my friends ask, 'Don't you need to maintain your image?' They tell me to maintain my image.  I wanted to have a bit of a friendly school life, so I approached people, but at first they would ask me, 'Is it okay for you to be like this?'"

SEE ALSO: Comedian Park So Young and former baseball player Moon Kyung Chan tie the knot

Baek Ye Rin said, "I've always been a bit closed off to strangers, so I'd put on my iPhone headphones, act chic, lie down, or even sleep at first.  But now, I got a lot more comfortable with the other kids, so I fool around and even ruin my image."

Park Ji Min said, "In the past, friends would greet me welcomingly with, 'Hey! Hey! Ji Min!' but now they don't really give a response," showing her disappointment.

Another guest, Park Si Hwan, also talked about his school days, saying, "I was really quiet.  I only had a few friends."