South Korean girl band, Twice. Facebook/Twice

Kim Sung Eun, is one such proud vocal trainer who has imparted music training to a lot of accomplished idols in her career. The songstress rose to fame after her appearance as lead trainer in reality girl group survival show, Produce 101.

Sung Eun recently sat for an interview with Sisun News, and revealed her favorite idols and shared stories surrounding them. She started off with the name of the most popular boy band, BTS. She said: "The first is BTS' Jin. One day, Jin suddenly sent me a song. He said, 'Teacher, this is a song you used as a lesson before. I tried recording it for real this time. Didn't I get a lot better at singing?' He was so amazing. Actually, that song doesn't have a proper MR, but Jin made an MR for himself and recorded it properly in a studio."

"I cried so hard at 3AM listening to that song. Jin is an amazing person. Even now, when BTS has a concert, he invites me whether it's in Korea or overseas," Sung Eun added.

Revealing her second option, the trainer shared her thoughts about girl group Twice. Sung Eun said: "TWICE has been #1 on the charts. During that time, they had opportunities to give their 1st place acceptance speeches on music shows. As soon as they got the mic, they said, 'Sung Eun-sunsaengnim, thank you'."

The songstress affirmed that Twice is the only group who ranked top and did not forget to mention her name in their speech. Sung Eun further added that while all her artists promises to say her name during the speeches, many forget due to overflow of emotions.

She said: "However, even though TWICE must have been overwhelmed by their win, they remembered me and said my name. Yesterday, I saw them at their label, and they ran over and hugged me. I was so touched."