Korogaru Hoshi no Asterism

In a Japan laid to waste by a meteorite strike, two survivors, Habane and Saku, travel the desolate landscape in a lone 4x4. They have a single goal: to journey south to a place where they can finally see the Southern Cross in the night sky. But their path is far from easy, as every person they encounter on the road is more eccentric, unpredictable, and dangerous than the last...

(Source: Kodansha, translated)