Wi-Fi can be connected anywhere, including airports, hotels, restaurants, and cafes.
The staff will be happy to tell you if you enter a restaurant or cafe, and ask "Tell me your Wi-Fi password." Also, since the password is often written on the receipt at the time of purchase, please check the receipt.
Almost any store is equipped with Wi-Fi.
It is very convenient because you can rent it at Japanese airport.
In that case, simply purchase a local SIM card and replace your mobile SIM card. (This method cannot be used on mobile phones with a SIM lock, so we recommend that you unlock the SIM lock in advance.)
Since SIM cards can be purchased from several hundred yen, it is recommended for those who do not need to make a phone call while on site.