If you want to get free wi-fi connection in Japan, you should download Japan Connected-free Wi-Fi (app). This app searches for free wi-fi.
★Free wi-fi spots in Japan (not all)
Convenience stores: Seven Eleven, Family Mart and Lawson.
Coffee Shops: Star Bucks, Doutor and so on.
The access points are locations most frequented by overseas visitors.
○ JR EAST Travel Service Center
Tokyo Station (Opening on October 1st), Narita Airport Station, Airport Terminal 2 Station,
Haneda Airport International Terminal Station (Tokyo Monorail)
○ 13 Stations
Tokyo Station, Hamamatsucho Station, Tamachi Station,
Shibuya Station, Harajuku Station, Yoyogi Station, Shinjuku Station,
Ikebukuro Station, Ueno Station, Okamachi Station, Akihabara Station,
Kanda Station, Maihama Station
○ Service available at areas near the sticker shown on the right
Free wi-fi areas supported by NTTEAST
Free Wi-Fi Japan supported by NTT EAST is a Free Wi-Fi service in the eastern Japan area.
Visitors to Japan can use NTT East Free Wi-Fi for up to 14 days, completely free of charge, on presentation of your passport.
The service is available in a wide range of areas inside and outside Tokyo, including: Tokyo, Hakone, Mt. Fuji, Yokohama, Nagano, Nikko, Kusatsu, Tohoku, Hokkaido, and lots more!
I will update.