Broadcasted on January 23, singer Seohyun was appeared as a guest on KBS Radio FM 'Park Ji Yoon's Space.'

When DJ Park Ji Yoon asked, "You're known to live a righteous life so much that you rarely speak in the casual form. Have you improved?" With that Seohyun answered, "I speak with the casual form when I'm with friends usually my age; however, it's difficult when I'm with older people."

The DJ then followed up with, "What is the most awful thing you've committed in your life?" The singer mentioned, "After I debuted, I went out with my friends dressed in halloween costumes. No one seemed to have recognized me as there were a lot of people around. It was so much fun taking photos, going to a bar, and chatting."

DJ Park laughed and commented, "The worst thing you've done was go around in a halloween costume."