April O'Neil is a young Human woman who has appeared in every version of the TMNT-franchise. April is usually the Turtles first human ally in most incarnations, and is generally portrayed as being a very good friend of the Turtles, often acting as a big sister/motherly-figure to them. April's love interest in the TMNT-franchise is Casey Jones, who's also a close friend/human ally of the Turtles.