On Nutaku's Facebook, they mentioned the name of the company that made this game, Kinkoid.

Based on their website and blog, the game was developed under the name "Hentai Heroes". Also it appears that originally they were just going to rip off existing characters and claim 'parody' which Nutaku obviously nixed when they agreed to publish. A bunch of the preview art is still up and you can see where they had to make edits, some more significant than others.

http://www.hentaiheroes.com/
http://www.kinkoid.com/

On another note, I'm shocked at the premium pricing in this game - kobans are so expensive and they get you so little. I can't imagine that anyone is thinking about actual spending the way this is balanced. I'm only still playing this because it has minimal time commitment.