McD's In Japan
Tasty Teriyaki Burger
Charging your electronic devices using any "unofficial" plug will get you into trouble. Trust me, I'm writing from firsthand experience. I was on a 7 day bicycle trip down South to Fukuoka and needed electricity desperately. I was at a hotspring and tried sneaking some juice while I was soaking in the bath but I got caught immediately.
Anyway, if you need electricity, the place to go is MacD's! MacDonald's are everywhere, especially by train stations and in malls. They have free plugs for charging anything you want. Also, you can purchase a battery powered juicer at any convenience store. However these can be costly. More expensive than getting a cup of coffee at MacD's and charging your phone!
Just remember to carry around your chargers.