I'm really glad you liked it! Have you tried picking up the axe by the weeping girl? The option should unlock when beginning the game with all the pages.
although we didn't get to implement a stronger connection to lore, we wanted to have it so that the weeping girl was the protagonist's friend (denoted by the "朋友" decal near her character). Upon learning that you need 6 bodies (after collecing the pages), the idea was that you now have a reason to kill even your friend. We never actually had the time to show this more clearly, as we wanted to finish the entire game within a week, and we also haven't playtested this, but I hope this ending still works!