

No trash cans in the parks around here. Train stations tend to only have trash cans on the platforms, not inside the station (just my experience, not definitive). You just learn to carry your trash with you until you find somewhere to dispose of it. I don’t see the big deal. If you do buy something from a street vendor say in a park or at a festival, they will provide a way to dispose of it. Also, it is not so common to eat whilst walking, so it reduces the problem considerably.
It would except for the fact that shoe sizes here, from babies to adults are only sized in centimetres. If there are international sizes printed on the shoes, they have no meaning to residents in Japan. Check the tag inside your shoes; If they have international sizes printed on them, you’ll see Japan’s is in centimetres, and may have EE (or more Es) next to it to denote width. If there is nothing, then they are standard width.
Children’s clothing is also sized in centimetres. Makes things really simple.