The average person in Japan uses over 60 pounds of plastic packaging per year, second only to the U.S.! Japan is covered in vending machines that dispense beverages in plastic bottles (though aluminum cans are still used for hot drinks) as well as convenience stores that sell lunches packed in single-serve plastic containers, so there's no shortage of plastic waste. In addition, when you open a package of snacks—like Oreos, for instance—in America, there's typically just one outer package. In Japan, each item in a package is wrapped individually. This is to prevent snacks from going stale since they are usually eaten in moderation over a period of a few days to weeks.
Yes and no. To be honest, I don't think that I've ever seen litter on the streets of Tokyo. Not even once! However, there is a brutal lack of trash cans in Japan. While we may be used to seeing public trash cans on the corner of every block or two in America, there are almost no trash cans in Japan, since trash cans attract litter! If you want to throw away your garbage, you'll just have to hold it until you reach a convenience store which could be anywhere from 30 seconds to 30 minutes away depending on your area.
In order to cut down on litter on the streets and within parks, retirees often volunteer to pick up trash in their area and sweep the streets free of debris. I would often see old men arrive at the crack of dawn to begin sweeping the path to my local park, only for the wind to blow the dirt back over the course of a few hours. In other words, the community in Japan has taken it upon themselves to maintain the constant flow of trash in their area, even if it means doing the same job every day!
