Just to follow up on what we actually did on our visit to Japan.
We rented a portable/pocket WiFi hotspot from Sakura mobile. Booked it on their website in advance and it was waiting at Haneda when we arrived.
They supplied and envelope to drop it into at the end and put in a postbox at Haneda on the way out. Super simple and trouble free.
The only downside is we had to reboot it daily as it would lose the cell service, but that was not a massive drama. You can tether a while bunch of devices which was convenient with two phones and two tablets. Worked fine on the Shinkansen too (even in all the tunnels).
We rented a portable/pocket WiFi hotspot from Sakura mobile. Booked it on their website in advance and it was waiting at Haneda when we arrived.
They supplied and envelope to drop it into at the end and put in a postbox at Haneda on the way out. Super simple and trouble free.
The only downside is we had to reboot it daily as it would lose the cell service, but that was not a massive drama. You can tether a while bunch of devices which was convenient with two phones and two tablets. Worked fine on the Shinkansen too (even in all the tunnels).