At Heart is back with their new track 'Butterfly Doors.' The comeback stage premiered on 'M Countdown.'
On March 19, 2026, the 'Butterfly Doors' comeback stage video was uploaded to the Mnet K-POP channel.
In the video, At Heart drew attention with their signature, original choreography. Their moves were so intriguing and distinctive that viewers said they "don’t copy other groups’ choreography."
This comeback is stirring especially mixed opinions about the styling and the song’s vibe. Many fans are calling for more unified outfits to better deliver a dreamy mood. Meanwhile, their skilled live performance is raising expectations among fans.
'M Countdown' is the world’s leading K-pop chart show, broadcast live every Thursday at 6 p.m. KST on Mnet.