Currently there's no scenes that requires lower purity (but there will be in the future~)
Ok, Leon said the mimic enemy might be able to lower it by losing/surrendering to it, the reason i ask about this was because of the waiter scene might have something new added if that stat is low enough to do so, same for any other new ones that might arrive in the future, this game is great so far, so take your time with whatever updates your currently doing, like the repeatable takes one that might arrive someday for farming as an example.
Hey hey~ thank you so much! Yes you can lower your purity by losing to the mimics~ (Might be spoilery but in my plan, lower purity might change dialogues with other people, lead to bad ends, and could have something to do with the tavern~ (I think).
Also, next public Update will introduce repeatable tasks! :3