From DrCoke at MangaHelpers:
17 year old Nowaki Asunaro has been forsaken by fortune since his birth. Every step he takes, bad luck awaits, whether it takes the shape of a falling bucket of water on his head or being blamed for crimes he never committed. Even for an exceptionally unlucky fellow like him, he still hopes to become friends with the love of his life: Hashihime Banri. The only problem lies in the fact that every time he almost gets close to her, his lack of luck blocks the way.
On one typical day for him, filled with unfortunate accidents, he ends up having to protect himself from the rain in a forsaken and dilapidated temple. He becomes feverish from cold and hunger, but in desperation, he prays to the gods that he survive this day and become friends with Banri. Lo and behold, it seems like he accidentally summoned a God(?). Will this accident bring him the luck he never had?