Is there a statute of limitations in K-pop that governs whether a subunit can still technically “debut” after they’ve been part of a larger group for 14 years? SUPER JUNIOR’s Kyuhyun, Ryeowook and Yesung (aka K.R.Y.) aren’t waiting to find out. When We Were Us is their official debut mini-album, a concentrated shot of balladry and slow jams from members of K-pop’s beloved group. The trio merge sentimental and centrifugal forces on “When We Were Us”, “Way to Busan” and “Home”, all lush Korean ballads. There is a light New Orleanian spring to “The Way Back to You”, while “Midnight Story” is a patio serenade after a late night—a jazz guitar and dandy pursed-lip whistle providing added atmosphere.