from boy band Exo and SM Entertainment's in-house record producer, Yoo Young-jin.

[1] On February 3, Girls' Generation's Taeyeon was the first to debut on this digital project through her release of jazz song, "Rain".

[5] The lyrics was written entirely by Yoo and narrates a monologue from a stupid man who had just realized his love after his lover left him.

[6] The song is considered as the follow-up to Exo's pre-debut single "What Is Love" which was originally released in 2012 and featured on their debut EP.

[7] Yoo composed and arranged the song in the key of C Minor, with the tempo of 120 beats per minute.