the way NG+ is handled in this game is not very well... now, i got ending a on my first playthrough so it's not a direct issue currently to me, but the gallery is saved only per save and not globally in the game itself including endings, AND lascivous points are also carried over the very thing that determines the ending, so for the sake of examples, if you got ending 3 or 4 on your first playthrough it's physically impossible to get ending 1 and 2 on that playthrough, if you want a full gallery you are required to get the endings in the order of A-B-C-D
would have preferred if NG+ started on day 1 y'know after the virginity loss, before any solo runs to the cellar, and only items, mana and scenes are carried over with lascivous points going down to 1 (it was at 1 after that point right?) would give more replay value instead of making it nothing more than scene collection after getting end A