Now sixteen years old and in High-School, attending Canterlot-High, Rainbow-Dash has found out that the gang responsible for her unbearably painful childhood is actually running the school! Undeterred by the almost-guaranteed chances of failure, RD makes it her mission to brutally and violently crush each head of this gang, and make it her own so that she may serve the vigilante-type justice that the streets desperately need. Oh, and yes, they are pretty much just anthropomorphic, different-colored humans.
This takes place in a setting similar to areas you'd usually associate with urban and gang-populated areas where there is a lot of criminal/gangster activity: a gangster-urban setting.

DISCLAIMER: There are very suggestive, realistic, morbid, violent, and GANGSTER like themes ahead! If you don't like it, then do me a favor as a writer/reader, and BACK OUT NOW! There will be so much language that it puts even the most ill-mannered mouths to shame. There is so much violence that it may just be sickening. The sexual themes will be shrewd, lewd, and realistic in terms of an urban, gang-populated city. You've been warned...

Credit for the sexy picture is below:
Picture Source: Graffiti 3
Author: Audrarius