Meowy keeps an exchange bin in his shop. If you bring an item you can take an item. Talk to Meowy about the bin.
This is the low-spoiler guide for "Meowy's exchange bin" puzzle in Nine Noir Lives. Unlike in normal walkthrough, you get gradual hints on how to solve the puzzle. Click the big button below to see your first hint. If the hint contains a spoiler, you will be warned about it before clicking.