Since there’s the harem tag, I’m guessing there’s a ending where you’re on good terms with all the girls, or do inventively have to give one or most of them up further in?
just use the walkthrough? it gives you a guide for every choice you make in the game, i read through it and from what i'm aware you can keep every relationship in the game though towards the end of it you do say some final goodbyes(but its the end of the game so it doesn't really matter
the harem ending is achieved by recruiting stabby mike for the final battle, you must not take astaroth's hand in the apothecary and you must not have grabbed the grimoire magnus in magnus mansion(though there is a secret ending if you don't complete any path and basically just choose every wrong answer)