This game is the reason why you play your own game before uploading it.
Anyway, I don't really see any content making replaying this game worthy but here is the way to get a good smooth experience.
Step 1. Olive oil Download Unren, run it in the game's folder and choose "9. all of the above"
Step 2. Play the game, after the first nun "event" if you choose the hate route she will catch you bonking your pet demon, the game will try to call up nunwatch2.png, will fail because there is a goddamn typo, so you go in game/images/CG/Nun and change the filename to the correct one and press enter. THERE IS A NEW BUG IMMEDIATELY. The game is trying to call up hero12ro in game/images/Sprite/No Blade and fails because that damn file doesn't exist. Now, your first instinct would be to grab hero12 which DOES exist, but that is a trap, hero12 is its own thing and needs to be called at times. hero12ro is the Right Oriented hero12 portrait. At this point you can do the right thing, copy hero12, open paint and flip the copy before renaming it to hero12ro. I just skipped the flipping part and did that, which now lets me know that you need to do the exact same thing and create hero2ro hero5ro, hero9ro and hero11ro. Which are all going to be called up in these scenes and don't exist.
Step 3. The worst is behind you but there is one last tricky move the game pulls, after autobuying the nun outfit, you will be unable to enter the main room of the hero's house in the middle of the day. The game tries to call up demonnun2.png, which doesn't exist, and since this happens while trying to setup the room being called up, ignoring the bug will cancel your move. To solve this you get into game/images/Sprite/Demon nun and realise that demonnun2.png does exist. It's right there. Even when counting the m's and n's and u's, you can see that the file name is correct. So what's going on? Look at demonnun1. It's called demonnun1, not demonnun1.png. The file the game is trying to call is literally named demonnun2.png.png. An old mistake but it did throw me on a loop for longer than I care to admit. Rename demonnun2.png as demonnun2, realise the same damn mistake was made for demonnun3, so fix it for good mesure.
At this point you'll notice the game is still bugged as all hell. Demon's love/hate parameter has negative hate (-1) while Charsi's has positive hate (+2) which one is correct? Don't know, don't care. Demon's quest objective "go to the town's square" doesn't show as completed, and the clothes started bugging for me after a while and I forgot how to switch them, if it's not somehow bugged in this version. Half the size of the game is due the backgrounds, as for H scenes there is one blowjob, one doggystyle scene and one out of focus image of a doggystyle scene. All with the same character. To call the game light on content would be the understatement of any year that is not 2020.
tl;dr when your game is 30mn long, do a playthrough before uploading it, damnit.