On the September 20th episode of 'Weekly Idol', Jung Hyung Don mentioned, "These days, Sunmi and Umji's friendship is getting noticed. How did you guys become friendly?"
Umji responded, "Rather than getting friendly, I wrote a letter to Sunmi sunbae with a shy heart. To be honest, in the past I picked Sunmi as the celebrity I'd like to receive a birthday congratulations from. I wasn't even thinking it was possible, but she remembered and wished me a happy birthday. I was so thankful I wrote her a letter."
Did you know Umji was such a big fan of Sunmi?