Digitally-colored version of a piece from 2012 that seems to be incredibly popular.
With this version I made the background a bit more detailed (now it really looks like she's outside the high school she goes to) and changed the pattern on her panties to bright red hearts (because they are cute).

The original drawing from 2012: http://lorddominic.deviantart.com/art/Alexis-Pantsed-336461305