The manga is about aliens coming to earth and supposedly saving it from a giant meteor that would have killed millions. The manga does make a point of how no one seems to have seen this meteorite so they're just basing it off what people in power and aliens say. So now they're celebrated unconditionally. There's a lot of immigrant allegory in it including complaining about how aliens can't speak the language but somehow get into high positions, how aliens drive dangerously and when they hit someone, cops don't want to investigate cause of diplomatic tensions. How aliens are celebrated etc while normal japanese arent and somehow most people are fine with this.

The end of the first chapter ends with the protags discovering aliens are delicious and vowing to eat them all