No, District 13 is a Paris set French film set in the near future (which itself has a sequel called District 13: Ultimatum - both of which are highly entertaining, btw) but nothing to do with District 9, a South African set SciFi movie. The District 9 spin-off is Wikus and Charlize, a short produced, directed, written by and starring the lead from District 9, Sharlto Copley, about the same character from District 9 bumping into Charlize Theron, playing herself (voice only), in a South African video store, and the subsequent hilarity/awkwardness that ensues.
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