Young songstress IU is a kid no more.

A clip of IU performing Park Ji Yoon’s infamous Adult Ceremony at her independent concert Real Fanstasy in Pusan earlier this month has been making its rounds online since it was uploaded onto a community message board.

IU sheds her cute, girl next door image in black short shorts and a tight-fitting tank top for the sexy performance, as she puts her own spin on the song’s signature body waves and leggy choreography.

Is the ‘Nation’s Younger Sister’ growing up too fast?

Decide for yourself in the clip below!