A lot of work went into this animation and there are many subtle things to discover. The gun detail was cranked up even higher then the previous animations and the characters were completely redrawn from scratch.
The story basically follows after the "Zombie Warfare I". The two are forced to survive by working together and going out at night for supplies. Food is hard to come by and it's uncommon to find any food that's not past it's expiration date. There's no utilities and there hasn't been another human sighting for a month.