[Dedime]

Aside from the point made by author - I visited Japan last year, I never had too much of an issue with garbage when visiting the major cities.

Most garbage was compactible and clean enough that I could stuff it into my garbage pocket (to the dismay of my girlfriend). Larger or dirtier items, I would put into a ziplock bag in my backpack that I carried with me everywhere. Public trash receptacles, while rarer than in North America, could be found often enough if you were observant of your surroundings.