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On the May 20 installment of the show, friends of 14 years Lee Hyun and Lee Jung Wook finally fulfilled their promise to perform together. Though they're both talented vocalists, both revealed they'd never performed on stage together before their 'Immortal Song' cover of Jun Wong Suk's "Don't Go". 

Lee Hyun expressed, "As I walked down the stairs, I thought of a lot of things. I used to perform in Hongdae with friends like K.Will and SGWannabe's Kim Jin Ho. Some friends did well career-wise, and some didn't no matter how much they tried. [Lee Jung Wook] is a friend who didn't do well," adding that he wished Lee Jung Wook's dreams to come true.

Lee Jung Wook commented, "It's an honor to be on this stage, and it's precious to be able to sing. I think it'll be a good memory. Thank you, hyung."

Spoilers Below:

Though their amazing friendship showed their chemistry on stage, it was Oh Yeon Joon and Yangpa who were the final winners this episode.