Paper for gum
The Japanese don’t have to search around in the bottom of their bags for an old receipt or post-it notes that they can wrap their used gum up in.
Their packets of gum actually come with little pads of paper which can be used for this exact purpose, and then you can just pop it in the next bin you see. The pads also have the bonus of being actual paper you can write on should you need to record your bank balance, the phone number of the cute barista, or your new business idea based around gum.