f(x)'s Luna opened up about late idol star and former groupmate Sulli.

On the March 3rd episode of 'Human Documentary - I Like People', Luna introduced her pet dog, saying, "I got my dog around the time we were promoting the song 'Hot Summer'. At the time, Sulli was so lonely that my mom and I decided that we should get a dog. The dog that came to the dorm was Bobby. Sulli's first dog." 

Luna also opened up about Sulli's passing, revealing she was so shocked she sat on the street and cried. She expressed, "Before Sulli went to heaven, she contacted me saying she missed me. She spoke to me informally for the first time in 15 years. She said, 'Unni, I miss you, unni.' I really felt that she sent the message after holding it in for a long time, so as her unni, I felt sorry. I should've gone to talk to her first. I should've at least said something. I should've told her I loved her more." 

In related news, Sulli passed away in her home in October of 2019.