No free Wi-Fi in Japan. This is true. There are some application like “Japan connected-free Wi-Fi” for travelers but it need to register your e-mail address. Maybe there is no all free Wi-Fi in Japan now. If you found some Wi-Fi in Japan, it must enter the authentication. It is the same in McDonald’s, Starbucks, Airport, Station, all Wi-Fi spot in Japan. There is a reason about it. It is to keep the law and order. When cyber-crime has occurred to found criminal particular will be difficult. If you found free Wi-Fi, there are the time limit for the connection of internet. Japan is called as a most safe country. Japanese government thoughts the convenience and safely. They chose the safe. There is some free Wi-Fi in Japan but it is inconvenient to use for foreigners.
Many Japanese do not have understanding of Wi-Fi. We all have a contact of mobile line along with the purchase of smartphone. I think people are recognized to have a tablet and laptop computer. Japanese people who has a smart phone in outside, they are not Wi-Fi connection rate of 99.99%.