Checkout is a thesis film by New York University students Dan Eckman, Dominic Dierkes, and Megie McFadden. It's about a ninja that works in a convenience store:
Black Shadow, a recently graduated ninja assassin, returns home from his training to begin his career; however, due to the tight job market, he is forced to take on a job as a stockboy at the local grocery. Mike and Drew, two fraternity brothers, hop from convenience store to convenience store exploring the competitive side of the “beer run.” And Janitor Joe goes to great extremes to prove to everyone at the grocery store that he can – in fact – be a “creepy janitor” as these three seemingly disparate storylines converge in a large-scale grocery store fiasco.
Link (don't miss the trailer!)