In Japan, it was totally free until about 10 years ago.
However, to save our earth, some supermarkets started non- free plastic bags. It is usually 2-5 yen per bag, and need to pay at cashier.
On the other hand, some shops another system. Plastic bags are free, but if you refuse it, you can get 2-5 yen discount from the purchase.
Other supermarkets still do not have any system about plastic bags, they just give us them by free. However, a lot of people are now using "eco bag" even if they are free.
Japanese eco bags are really cute and strong. Some of them have useful idea and really comfortable.
Which do you like the best?