As Japan is a densely populated country, it has a major concern with garbage disposal.
Garbage disposal is the responsibility of local governments, and they take various steps to limit the amount, especially by encouraging recycling. In the city where I live, recyclable items can be put out as garbage for free, while in principle burnable garbage and other non-recyclable items have to be put out in colored bags purchased from the city. The city publishes a 117-page booklet to help its residents sort garbage correctly, and I find this booklet to be a necessity.
However, a few types of burnable garbage can be put out free. To support families with small children, disposable diapers are free garbage, and garden trimmings are also free, as greenery benefits everyone.