We only got bad ends rn, but we got goblins, orc giant, and homeless people. Basically just drop Kohaku's love stat to 0 and then wait like 5 days to get each one. Also there's the milk end, where Kohaku gets stolen by some cow human abomination in the town by the capitol. Aside from that, the story has at least two endings that I know of, though the story hasn't concluded, so neither has been fully implemented.
Alright, so if you don't mind using cheats, you gotta set yourself into Event Test Mode, which will allow you to choose Level 5, which is the strangling sex. If you do mind using cheats, then you have to manually raise Yarizo's addiction level by just winning a bunch of fights with him in the party or using event circles and NTR at the desk in the room at the inn. You can probably grind rats in the sewer for this. Level 2, 3, and 4 seem to be empty, so I'm a little disappointed there.
So recently, the dev changed the way it works. It used to be your stats decided the number of dice you rolled, but it's been downgraded to just being a flat bonus to your check. The Success is at 32, so you'll need at least a 20 in Strength to clear this. Only issue is that there's no 'legal' way of getting 20 strength. So you gotta whip out a save editor and give yourself a bunch of skill points to upgrade your Strength or figure out which number corresponds to strength and just max that out.