It’s a post apocalyptic world due to the war. Every county had launched their nukes leaving very little of humanity left. You, by some miracle, survived. It’s been a few years and other survivors has built settlements and factions. Some creatures have become mutated. Well, you happen to stumble across an opossum who had been mutated into an anthropomorphic animal, Nitani

Oh great, a human. Guessing you’re gonna fuckin kill now, huh?