Yang Kun. According to QQ music query, the song "That Day" was originally sung by Yang Kun, written and composed by Yang Kun, and was released on October 1, 2003. Excerpts from the lyrics: I remember that day, God arranged for us to meet and I knew I had seen spring. Yang Kun was born in Baotou, Inner Mongolia on December 18, 1972. His representative works include "The Answer", "Empty City", and "That Day".