Aachi & Ssipak.

Sometime in the future, mankind has depleted all energy and fuel sources, however they have engineered a way to use human excrement as fuel. To reward production, the government hands out extremely addictive, popsicle-like "Juicybars", which in turn also act as a laxative. Aachi and Ssipak are street hoodlums who struggle to survive by trading these bars in the black market.