BTS watched and reacted to their debut stage. 

In celebration of the 600th episode, Mnet's 'M Countdown' interviewed idols such as BTS and MAMAMOO, who had their debut stage on the music show. The groups also took the time to watch their very first performance again. 

On January 9, Mnet released the full video of BTS reacting to their debut stage. The boy group debuted with "No More Dream" in 2013. 

Check out what BTS members have to say about their debut stage in the clip!