I don't really know how true it is, but it seems someone got a bit of information
Viewing post in Daily Lives of My Countryside comments
so far it seems like it will be the mc "transform" into some kind of beast.... but considering he promised long time ago this game won't have zoo shit.... it shows how much this dev likes to lie and break his promises.... also his beta tester has always been trying him to add sex with the horse and all that crap content... it seems this dev is finally falling and being convinced into adding crap his sick beta testers wants.