Before you start

Residence card with address printed
A Japanese bank account or credit card, for most postpaid plans
An unlocked or eSIM-capable handset
A Japanese address, for fibre

Step-by-step

1
Use a travel eSIM for the first days
A data-only eSIM bought before arrival covers you until the residence card and bank account are sorted, which can take a fortnight. It removes the pressure to sign something unsuitable in your first week.
Mobile appWho: YouDay 1
2
Go straight to an MVNO or a carrier sub-brand
IIJmio, mineo and the carriers' own low-cost brands run on the same networks as the majors at a fraction of the price, with no long commitment. mineo in particular is a Kansai company and is well established locally.
OnlineWho: You
3
Expect a Japanese payment method to be required
Most postpaid plans require a Japanese bank account for direct debit or a Japanese-issued credit card. A foreign card is frequently rejected, which is why the bank account comes before the phone contract.
OnlineWho: You
4
Check the building carefully before promising anyone a stable connection
Kyoto has a great deal of older housing, including traditional machiya, where fibre installation may require the landlord's permission and physical work that a heritage-sensitive building will not permit. Some addresses in the central grid genuinely cannot get fast fibre. If your work depends on it, make it a condition of the lease rather than a hope.
OnlineWho: YouBefore signing a lease
5
Ask about student and university connectivity
Kyoto's universities provide eduroam and often assist with home connectivity for international students and researchers. If you are affiliated with one, ask — it can resolve the problem entirely.
Via employerWho: You
6
Keep your number when you switch
Japan operates mobile number portability and has simplified it considerably. Never cancel the old contract before completing the switch.
OnlineWho: You

Documents you’ll need

Residence card with address
Japanese bank account or credit card
Passport, occasionally requested
Landlord permission, for fibre installation in older buildings

Things most newcomers don’t know

A machiya may simply not be able to have fibre, and that is a lease-signing question.

Kyoto's traditional townhouses and much of its older central stock were not built for cabling, and heritage protections plus landlord reluctance mean some addresses cannot get a fast fixed connection at all. Coverage maps will show the street as served. If your income depends on the connection, get the landlord's written agreement to installation before signing, or accept that you will be working on mobile data.

Source: community-reported

The bank account gates the phone, not the other way round.

Most Japanese postpaid plans require a Japanese bank account or a Japanese-issued credit card, and foreign cards are commonly rejected. Since the bank account requires ward registration, the whole chain runs address → ward office → bank → phone. Trying to do it in any other order is where first-fortnight frustration in Japan comes from.

Source: community-reported

MVNOs run on the same towers for a fraction of the price.

Government pressure on the three major carriers produced both low-cost sub-brands and a healthy MVNO market, all using the majors' own networks. Coverage and speed are essentially the same outside peak congestion. Anyone paying a flagship carrier price without needing the bundled extras is paying several times more than necessary.

Source: Ministry of Internal Affairs and Communications

Japan's 100-volt mains and 60 Hz western grid catch people with appliances.

Japan runs the lowest mains voltage in the world at 100 V, and western Japan including Kyoto uses 60 Hz where eastern Japan uses 50 Hz. Appliances brought from Europe will not work without a transformer, and some older Japanese appliances bought in Tokyo behave differently here. Chargers and laptops are fine; anything with a motor or heating element is not.

Source: community-reported

Common mistakes to avoid

Signing a lease on an older property without confirming fibre can actually be installed.
Trying to get a phone contract before ward registration and a bank account.
Signing a flagship carrier plan when an MVNO on the same network costs a fraction.
Bringing appliances that cannot handle 100 V at 60 Hz.
Cancelling an old contract before completing the number transfer.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.