Their agency, JYP Entertainment, announced, "NMIXX will make a surprise comeback with the release of their 5th mini album, 'Heavy Serenade,' on the 11th of next month at 6 p.m."

Along with this announcement, they posted a promotional scheduler image on NMIXX's official social media channels, building excitement for the comeback.

Just like the album title 'Heavy Serenade,' this scheduler image boasts a romantic atmosphere featuring musical staffs, treble clefs, notes, and musical symbols.