While I personally think that piracy would be acceptable in a case where the developer and publisher are unable to profit from a game, this seems kind of intentional.

If nobody could produce a contact address here, you could try to find archives of their various sites through archive.org. They might have an email - or at least further links you could try.

I hope you can solve this mystery - and maybe share the resolution with us when you do. :)

Sorry that didn’t work out. The only other thing that I could think of would be to reach out to somebody who covered one of Okamizt Studio’s games (a games journalist or a YouTuber). While they wouldn’t be able to provide you a copy, they might be willing to share an official email address for you - or might even know what’s going on with that studio.