https://www.gog.com/game/summer_memories_deluxe_edition_unrated
basically, the game is censored but the uncensored patch comes as a free DLC so one can go around Paypal prudors. the patch is on GoG aswell and not on the website of the game makers like it use to be for steam
source is 4chan: https://arch.b4k.co/v/thread/580218447/
I don't think it's that new. At least, earlier this year I got a GOG mailer for "adult" games. The most popular was some bullet hell game with sexy characters for some reason.
At least this one is free.