@MarqFJA87
I remember starting to read this on an imageboard where some kind soul did soft translations. A long, long time ago. Six years ago, it seems, then. I'd have thought it was even more.
I reckon nothing he made before this ever sold well. As I understood it, this was just a doujin in the beginning he posted somewhere. Then it got popular to the point of getting an anime. This must have been his first work that sold.