Buy an eSIM before you land. Sort out data at the airport, not later.
You will use maps and timetables constantly here, and public wifi in Japan is patchy and often requires registration in Japanese. Getting data on your own phone is the single practical thing that makes travelling here easy.
There are three ways, and all three are available at every arrivals hall: an eSIM bought before you fly, a physical prepaid SIM from a counter or vending machine, or a pocket wifi router hired for the trip and returned at the airport.
Pick by how many people you are. Travelling alone, an eSIM is simplest. Two or more, a pocket router is cheaper and keeps the whole family on one battery. charge.
A prepaid SIM card or a pocket router works on any phone, and both are sold at the airport and in the big electronics shops. You do not need an eSIM to get online here.
Download offline maps of the areas you are visiting. Signal fails in tunnels, in mountains, inside old buildings and on ferries — and that is exactly where you need a map.
Buy an eSIM before you fly, or collect a SIM or a router at the airport. Prices change constantly, so compare on your dates rather than trusting a fixed figure.