Don't worry, it's not as though the information is "needed" in that there are rules or anything (not that I'm aware of, anyway), and more just that making the question more specific can lead to more useful answers.
But similar in every way except the beastiality stuff... so similar art, gameplay and fetishes. Hm. That's a tough one. It's a lot of boxes to tick.
Allowing a little leeway,
Town of Passion and
Daily Lives of My Countryside have been frequently recommended in this thread in the past, and both have similarities to Bones Tales: The Manor. They both have 2D art, are RPGMaker games, have young-looking male player characters and both feature incest, among other things. Daily Lives is probably closer to The Manor gameplay-wise, whereas Town of Passion has quite a few more-or-less inventive puzzles and run-away-from-the-enemy combat.
I've also seen
Summertime Saga recommended a bunch of times by a lot of people who seem to think it's the best thing ever, but I haven't tried that one myself and can't personally say it's a suitable alternative. It seems superficially similar and is highly rated, so it might be worth a look.