A couple months after this game's release the artist had a severe medical emergency that has seemingly forced him to retire. Tsukumo Kazuita hasn't published any artwork and SYRUP hasn't released a game since. Beyond the empathy for his health and loss of work, It is too bad, because both the quantify and quality of the artwork in the game is of the highest level, assuming the fetishes included work for you.
He last tweeted less than a month ago, so he is still alive, fortunately, but you can read though his tweets starting around April 2014 to see some of what he as gone through. i have to read through a machine translation so i can't comment on specifics with any certainty.
@nonamesleft Dang, that's sucks. Really love the game's art, though can't say about the anime (PoRo really ruined it for me). Hope he'll recovers soon and start working again.
Also, thanks for uploading the character set, near2417~