Written by K-Smith and Cho Young-soo, "We Were In Love" is a poignant ballad characterized by its melancholic melody, blending orchestral strings, a gentle piano arrangement, and subtle acoustic guitar, with the violin and piano serving as the central instrumental themes.

The official music video premiered on December 22, 2011, on South Korean media player GOMTV.

The video alternates between scenes of the members reminiscing about happy moments with their past lovers and the sorrow they feel after the breakup.

Soft lighting and melancholy expressions highlight the themes of heartbreak, while the video concludes with the members accepting the end of their relationships.

[4] Upon release, "We Were In Love" quickly topped digital charts on various streaming platforms such as Soribada, Mnet, and Bugs!, achieving an "all-Kill".