The song was first uploaded on April 28, 2008 and is Hikutsu-P's sixth original work. It's Hikutsu-P's first work to feature Kagamine Rin, and second to feature Kagamine Len, the first being "Mou iyada!".
It is said on Hikutsu-P's description that the song was made during the graduation season, and has a somewhat graduation-like theme to it; much like how Halyosy's song "Sakura no Ame" themed. However this ballad song is up for anyone to interpret. On February 12, 2011, Hikutsu-P made an append arrangement of it entitled "ver.2011 Append" with the vocals being Rin Sweet and Len Power as one of the tracks for his album "Yellow&yelloW".
"Wadachi" tells a story of two who talked about life. May it be happiness and sadness Len had always been there for Rin, and vice versa. Overall it tells a story of not giving up, so long as they have each other.