After studying Japanese language and culture for the last 15 years, and spending about 6 months there in total, I would say they have a massive over-packaging problem in general.
I've never seen a place throw away more plastics than in Japan.
If the current oil situation forces a reworking of this system, I'd say all in all, that's an upside.
Japan is nowhere near the worst for plastic waste per capita, and it has very high recycling rates.
Rely more on statistics and less on personal observation.
Japan can package up all the snacks they want, they still use far less oil per capita than the USA.
Japan: Approximately 28% of all passenger kilometers are traveled by rail
United States: Rail travel accounts for only about 0.25% of passenger kilometers
Remember: when you drive your 30mpg car to work, 20 miles down the freeway, alone in your vehicle by yourself, you are burning over a gallon of refined petroleum product every single day. You can make a loooooot of plastic bags with that much oil.
Something like 95% of Americans get to work via automobile.
Nippon packaging
So dressed like a lover
Frigid winter day
The actual canned response to this is [1] and humidity. Daily levels of humidity in East/Southeast Asia is whole another level from US/EU(or vice versa).
1: https://en.wikipedia.org/wiki/Glico_Morinaga_case