In this week's episode, several incredible groups make a comeback! The four ladies of MAMAMOO are back as the coolest hipsters and NATURE introduces their newest member with their song “OOPSIE”. IN2IT takes viewers to another world with “ULlala: Poisoning” and SOUTH CLUB sings the sweetest breakup song. Other performances include GOT7, VICTON, HyunA, and more. Stay tuned!