Wow I had no idea of this game, I'll try to get in contact with itch.
Thank you for bringing this to my attention!
itch was contacted almost a week ago. they sit on those reports or they ignore them or they do not believe them. maybe they listen to you. or others reporting the fake.
to tell the truth i did not even know the original was on itch too. but games hosted on dlsite do not appear here on itch as a free full game, just like that. when itch did not remove it from index after several work days, i wondered why the impostor did not use the correct spelling...
so i hope this is not some plot twist, and there are two impostors, since you do not link to dlsite, but the fake project does. ;-)