LUCIFER AND THE BISCUIT HAMMER (Hoshi no Samidare), by Satoshi Mizukami. First published in 2005 and first published in North America in 2014.
PLOT:
Yuuki is an ordinary guy with an ordinary life and because of that he can't seem to muster up any sort of strong emotion about anything. He spends his days drifting through life alone...at least, until he meets the talking lizard Noi. He tells Yuuki that he is a magic knight who must save Earth from destruction by a giant magical hammer. Yuuki takes this about as seriously as you might expect, but he finds himself convinced when he meets Samidare. She's a friendly girl with super strength and a desire to win so that she can destroy the world herself. It's a bizarre motivation to say the least, but it's just the thing to convince Yuuki to join her cause.
