3.24 out of 5 from 105 votes
Yuuhi Amamiya is a loner whose mistrust of people was instilled in him at a young age by his abusive grandfather. So when an annoying talking lizard tells the university student that he is one of twelve knights chosen to stop the gigantic "biscuit hammer" before it smashes the Earth to smithereens, Yuuhi has no inclination to rescue such an unkind world. Despite his apathy, the boy is targeted by a golem while going about his day-to-day life, and ends up teaming up with the other knights anyway. One of his new companions is Samidare Asahina, the "princess" and leader of the knights, who secretly is only trying to protect the Earth so she can destroy it herself! Entranced, Yuuhi swears eternal loyalty to this cheerful devil that promises to crush the world he despises.
Both manga feature saving earth (or maybe just a single prefecture) from a large object falling from space and a laid back protagonist. On top of that both were written by the same person. It's highly possible that you'll love one if you liked the other.