Would this game ever have an "ending" so to speak, like if we completely 100% a girls storyline we can choose to settle down with her, or like just stay single but rich with an inn, or a loser ending, stuff like that?
Though of course in the distant future, I am definitely planning for an end to the game. Likely the default ending would be the "harem ending" in which you would see short epilogues for each character you romanced to a certain level, and then there would also likely be a "one true love" ending if the player stays true to one specific girl for the whole game. Other than that, I'm not sure, possibly other endings, it would depend on how the story shakes out in the end.
And of course, the player would be able to continue playing after viewing the "ending".