Staying online in Japan without a roaming bill

The expensive way to get online in Japan is to land, open a map, and let the home line roam while you look for a SIM counter. The line you already pay for will do that cheerfully. Turn data roaming off on that line before the wheels are down, or before you leave home if you do not trust yourself in the airport.

An eSIM is the usual fix for one phone. Buy it before you fly and install it while you still have wifi, because the setup often wants a connection you are about to lose. A phone with no physical tray has no other option. A pocket wifi, the little router you pick up and return, is the better buy when several people need to be online and only one of them wants to manage a plan. One device, one password, and the phones stay on their own numbers for calls and bank texts.

Before you lose the wifi you have

• Install the travel eSIM, or confirm the pocket wifi order, on the morning you leave.
• Set the home line so it does not use mobile data. Wifi can stay on.
• Download offline maps for the cities you will actually be in.
• Keep a screenshot of the hotel address. A driver cannot read it from a dead screen.
• Narita, Haneda, and Kansai have counters if you did none of this. The queue is the cost of that choice.

Roaming charges are dull and real. The home bill arrives after you are back, which is a poor moment to learn that the map was expensive. The travel plan is the one you meant to use. The home line is for the number that receives your codes, preferably on wifi.

Test the new line before you need it for a train. Join the airport wifi, confirm the eSIM is on, then open a map. If it fails in the terminal, the counter is still in the terminal. If it fails on a platform in Shinjuku, you are navigating a station from memory.

Save

What the connection is for

You need it for the train time, the hotel pin, and a translation when a menu has no pictures. You do not need it to stream a show on a packed carriage. Download that at the hotel. A silent phone is the whole manners rule on the train, whether the file was saved or not. A hot spot held up in a crowd is just a larger phone.

Pocket wifi batteries fade in the afternoon if the device has been bridging several phones since breakfast. Charge it at lunch. Put one person in charge of it so it does not stay on a cafe table. An eSIM does not have that problem, and it also does not share. Pick the tool that matches the group you have.

Write the login down. A pocket wifi password that lives only in an email you cannot open, because you have no connection, is a small scene you can skip. A note in the wallet still works when the phone does not.