Takers – 오빠라고 불러줬으면 (Wish You Call Me Oppa) 

From Soompi:

“Takers made their debut on “Super Star K” Season Four as contestants. The duo consists of members Pink (Ahn Jung Suk)  and CoE (Park Sang Wook), and rose in popularity with their cover of Lee Hyori‘s “Remember Me.” A year after their official debut, Takers has made a name for themselves as a duo who bring quality sound with their pleasing and versatile voices.”