Note: I did this with a Samsung Galaxy S4, American AT&T model.
So you’ve decided that you want to keep your original phone from your country and only get a sim card in Japan. I’ve been using IIJmio which is one of several options. You can check on your phone company’s website to see if your phone will be compatible with NTT Docomo’s network or check here! Requesting the sim card took me about 5 minutes with the help of Google translate: I don’t know any Japanese! They have data only plans, SMS + data, and a calling, SMS, data plan. I have the last where you pay per minute of call and to send text. You can tether for free. You can cancel whenever you’d like. Extra data also rolls over. The prices before tax:
an unlocked phone
a credit card (I used my US one)
clear pictures of the front and back of your resident card
Signing up for the sim card:
This is the process for buying from the IIJmio website. You can also get the sim card via amazon or at BIC Camera.
1) Go to the IIJmio website. Click on the sim card, then select the first option for a sim with calling capability.
2) Scroll to the bottom of the page and select the green button.
3) First you must make a mio ID so select the green button on the left.
4) You haven’t bought the sim card yet so select the left, green option.
5) Scroll down and you’ll see a bunch of agreement text. Select the box, I agree, and click the green button.
6) Now you have to make your selections:
Plan - 3, 5, or 10 GB per month
Function - pink one if you want calling, blue is data only, green is data and SMS. It’ll ask if you want a new phone number or to transfer one so select the first box for a new number.
Sim card or/and phone - the pink box for just the sim card
Sim card size - My Samsung Galaxy S4 uses a microSim which most newer phones do.
No extras for me. Then select the green button.
7) Now you have to input all your personal info. I didn’t add my middle name anywhere. At the end you can click the green box to continue.
8) Next page will be an email confirmation page. They will send a four digit code to your email that you will have to input within 30 minutes back at the IIJMIO website.
9) Two minutes later, I got my mioID email titled “please confirm your mioID” but you don’t need to do anything, but keep your ID. I also got a thank you for your order email at the same time. The third email “本人確認書類画像のご提出について” was about submitting your identification documents.
10) Login here using the Login ID from that last email. A string of numbers and letters that have your mioID in it (crossed out in red in the pic) and the password: your 8-digit date of birth (example: January 1, 1980 → 19800101)
11) Upload the images of your documents on the next screen. Open the terms and agreements in the green area before being able to check the checkbox.
12) Next it’ll show what you uploaded and examples of bad photos.
The drop down box will ask you what type of evidence you uploaded. I have selected residence card. Hit next to go to your second photo, select the same residence card box, and then hit confirm, the second option at the bottom.
13) After completing the image upload, I got a confirmation email: 本人確認書類画像受付完了のご連絡. Four hours later I got the email 本人確認完了のご連絡 saying my images were confirmed and that it would take about a week to deliver.
14) Two days later I got the ready to start email with the details of my plan and tracking number for the sim card. And it was delivered the next day. The whole process took 3 days for me.
Putting in the sim card:
You should turn your phone off and put the sim card in. After turning your phone on, if your phone isn’t unlocked, it’ll ask you for your unlock code. Input that if needed.
In order to get data, I then had to configure my phone’s settings. It immediately said NTT Docomo on the top so I knew I got service. This will differ from phone to phone.
Settings - More networks - Mobile networks - Access Point Names
If IIJmio is listed, just select it, otherwise add a new APN using the plus sign and enter the following info:
PAP or CHAP
3) Then I had to restart my phone again, and ta-da, 4G LTE was working.
With different models of phones, this last step will vary quite a bit.