Haneda is the closest big airport to central Tokyo, which means you can be sipping coffee in Shibuya within an hour of landing - as long as your phone works. Install a JamboSim Japan eSIM before you fly and you step off the plane already online, ready for train apps, maps and translation.
Haneda has free Wi-Fi in the terminals, but it stops the second you board the monorail. An eSIM keeps you online from the gate all the way to your hotel.
The Tokyo Monorail and Keikyu Line both leave from under the terminals and reach central Tokyo in 15-30 minutes. Ticket machines and IC card apps are far easier with data.
Haneda has three terminals (1, 2 and 3) connected by free shuttle buses and walkways. Local time is Japan Standard Time, with no daylight saving.
GO is the main taxi app in Japan
Yes. As soon as your phone connects to a Japanese network it comes online, usually while you are still taxiing or walking to immigration.
Install it at home over Wi-Fi and switch it on when you land. Installing needs internet, using it does not.
For most travellers, yes: nothing to collect, nothing to return and no extra device to charge.
