철규 – Rainy you
Track 01 from Single "On The Night Of December Last"
Release Date: 2016.12.26
철규 – 작은 사람
Track 01 from Single "Respectable"
Release Date: 2016.06.08
Manuka (aka.에스더김), 철규 – Come to me
Track 01 from Single "Come to me"
Release Date: 2018.08.20