This song was featured in the ninth episode of "Ghetto Justice", and was specially made for this series. Stephen Wong's character sang it to his sister, Katy Kung.
"Mixed Up" - Stephen Wong
交錯 《怒火街頭》 插曲 - 黃嘉樂
Personal Note: Like Lorretta Chow's song, "You Are My Angel" in "Forensic Heroes II", nice to see that TVB also tailor-made a song in this series. :)
Also, Stephen Wong doesn't have lazy sounds when he sings! ;)