Investigating Japan SIM cards? If you balk at the steep monthly fees and hidden charges of the big mobile players like NTT DoCoMo, Softbank and AU, you might have contemplated going the “SIM-free” route—ditching your locked cellphone for an unlocked handset paired with a cheap MVNO SIM from one of the plethora of vendors that have seemingly popped up overnight.

Note: The focus of this post is on longer-term SIM use in Japan. For a comprehensive guide to the whole mobile data scene, with an emphasis on Japan SIM cards for short-term stays, see our sister article on Your Prepaid SIM Card Options in Japan.

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Introduction to Japan MVNOs

MVNO stands for “Mobile Virtual Network Operator”, which means an operator that piggybacks on the network of one of the major players. For most MVNOs in Japan, this means using mega provider NTT DoCoMo’s high-speed LTE network. In general, the offerings from MVNOs in Japan are so much cheaper than the cabal of three (sorry, but Y! Mobile is just SoftBank in disguise, with even worse service), that for saving money you should just change right now. This minute.

The problem is that there are so many different Japanese cellphone plans that it can be hard to choose. Mobal, Sakura Mobile, BIC SIM, Biglobe, DMM Mobile, IIJMIO, Mineo, Nifmo, Rakuten Mobile (now partly using its own network), Nuro Mobile, LINE Mobile and U-mobile (now y.u mobile) are just some that we know of—there are possibly quite a few more. Our basic advice when looking for an MVNO in Japan is to consider three things:

  • Amount of data
  • Cancellation fees
  • English-language support

Anything that answers lots, none/low and yes to those (in order) is worth considering, in our books.

Changes to Japan SIM pricing

Note that mobile contract cancellation penalties have been reduced from late 2019, following a government ruling to this effect.

Also, in response to requests from the Japanese government, the major telcos players started offering cheaper plans from March, 2021. These include DoCoMo’s ahamo plan, kddi au’s povo, and SoftBank’s LINEMO. The plans are in the range of ¥2,730¥3,000/month, tax included, for about 20GB of data. However, adding a voice call option could push up the price quite a bit. You are advised to read the T&Cs carefully, if you are interested in one of these plans.

The two basic Japan SIM card types

Japan SIM plans are divided into two different categories—data only, or data + voice. Just because you get data only, it doesn’t mean you can’t text using SMS—most providers have an option for this (it just costs a bit extra). Without the voice option, you won’t be able to make or receive regular phone calls, but Skype, WhatsApp, Line and other apps that allow calls over the internet (using data or wifi) will work.

To save you the time of trawling through all the Japanese mobile carrier sites and all the fine print, we have prepared comparison charts for some of the most popular data-only SIMs and data + voice options, with a focus on the MVNOs. We even added sales tax, since some companies conveniently leave it out because well, it’s just so difficult to add 10% to everything right? Poor sneaky things. Note that these options are by no means exhaustive.

Data + voice SIMs

Data + voice SIMs differ to data-only SIMs in that they typically have a minimum contract period and cancellation fees. Just like the data SIMs, they have a starting fee of approximately ¥3,300 (Sakura Mobile’s set-up is a little different, though). They all charge somewhere in the region of 29-47 yen/minute for voice calls and 3-30 yen for sending domestic SMS texts. Receiving texts (both domestic and international) is free. Billing is monthly.

All prices in the table include 10% consumption tax.

Provider Data + Voice Plans (Tax incl.) Min. Contract Cancellation Free Contract Suspension English Support Link
Mobal 7GB: ¥4,500 No contract ¥0 Pricing info
4GB: ¥3,278
25GB: ¥4,378
No contract ¥0 Pricing info
Biglobe 3GB: ¥1,320
6GB: ¥1,870
12GB: ¥3,740
20GB: ¥5,720
12 mths ¥1,100 × × Pricing info
IIJmio 2GB: ¥858
4GB: ¥1,078
15GB: ¥1,848
20GB: ¥2,068
1 – 2 mths ¥0 × × Pricing info
Nifmo 3GB: ¥1,760
7GB: ¥2,530
13GB: ¥3,850
30GB: ¥4,730
None ¥0 × × Pricing info
Unlimited: ¥3,278 None ¥0 × × Pricing info

Notes on above:

Mobal – When your monthly cap is reached, data is still available at reduced speeds. ¥1,000/month voice + text plan also available. Domestic SMSes at ¥12 each. No resident card or visa requirements. Bulk of profits go to charity. If you’re traveling from China, you have access to a range of other packages.
Sakura Mobile – Although there are no cancellation fees, there is an all-in-one ¥16,500 “activation” fee, often discounted to ¥5,500. Flexible payment options. Student discounts.

Biglobe SIM – Discounts may be available on long-term plans.
IIJmio – Often run promotions.
Rakuten Mobile – Recently launched their own network. 1GB, 3GB and 20GB deals also available. Speeds may differ depending on your area. Unlimited local calls and texts through the Rakuten Link app.

With some of the other plans mentioned in this article, it may be possible to reduce call rates by using proprietary data-based apps. Although not explicitly stated above, many plans also allow data sharing with partners and family members. Note that other plans may be available in addition to those listed above. Tethering may also be possible. Data services may continue, though throttled, once the monthly limit has been reached.

Japan SIM mobal
Photo by Carey Finn

Data-only SIMs

As above, there are certain things that all plans share. For example, they generally have a “starting fee” (they have different names for this) of roughly ¥3,300. But unlike data + voice SIMs, data-only SIMs often have no set contract period or cancellation fees. Also note that for the additional feature of SMS, you will generally pay a small monthly fee (80-130 yen a month), plus 3-30 yen per domestic message sent. Receiving SMS messages is free.

All prices listed include 10% consumption tax.

Provider Data Plans (Tax incl.) English Support Monthly SMS Fee Link
4GB: ¥2,728
25GB: ¥3,828
¥0 Pricing info
Biglobe 3GB: ¥990
6GB: ¥1,595
12GB: ¥2,970
20GB: ¥4,950
× ¥132 Pricing info
IIJmioIIJmio 2GB: ¥748
4GB: ¥968
15GB: ¥1,738
20GB: ¥1,958
× ¥77 Pricing info
Mineo 5GB: ¥1,265
10GB: ¥1,705
20GB: ¥1,925
×  ¥0 Pricing info
Nifmo 3GB: ¥990
7GB: ¥1,760
13GB: ¥3,080
30GB: ¥3,960
× ¥165 Pricing info

Notes on above:

Sakura Mobile – Activation fee of ¥5,500. Unused data accrued to following month. Flexible payment options available.
IIJmio: Japan eSIMs available.
Mineo – 20GB data, as well as data-and-voice plans available.

With some of these mobile network providers, it may be possible to split one data plan among multiple SIM cards—this is great for families/couples. Tethering may also be possible. Ask when applying. Note that other plans may be available in addition to those listed above.

Unlimited data SIM cards in Japan

We don’t know of any unlimited data SIMs in Japan that allow you to do endless stuff on the interwebs at the same fast speeds forever. Packages that are described as offering unlimited data generally have a fair usage cap after which speeds get slowed down—meaning you can still do stuff on the internet, but maybe only at a (pre-climate change) glacial pace. Anecdotal evidence suggests there was once a time of unlimited (or almost unlimited) data on some of the Japanese mobile carriers—but those heady days seem to be over.

Payment options

One of the most frequently asked questions is how to pay for a voice + data or data-only SIM contract in Japan. All of the providers accept Japanese credit cards, but unfortunately, some do not accept international credit cards. Mobal and Sakura Mobile are okay with international cards, and also allow payment by cash at convenience stores. For all the others, ask at sign-up.

Number portability: How to keep your number when switching carriers in Japan

Rather than give up your phone number everytime you want to switch cellular providers, you can take your number with you (with many carriers, anyway). This system is known as Mobile Number Portability (MNP), or porting for short. Most of it can be done online or over the phone, but this is Japan—so of course it’s all in Japanese. To keep your number while switching carriers, follow these steps.

  1. Apply for an MNP number through your current carrier. Don’t cancel your plan before doing this!
  2. Sign up for a plan with your new carrier, and select the option for switching and enter your MNP number.
  3. Wait for your new SIM card to arrive—don’t remove the old one yet!
  4. With your old SIM still inserted, call the free number or follow a link provided by your new carrier for activating the new SIM.
  5. Enter your phone number and some digits from the card your new SIM is attached to.
  6. As a last step, swap out the old SIM for the new SIM, and follow the instructions for setting up your APN (android) or profile (iPhone).

More options for mobile internet connections in Tokyo

Watch our short YouTube video on getting hooked up with wifi in Japan and investigate some of the best wifi router rental options. You might also consider cellular roaming, or an international e-SIM.

While we do our best to ensure that the information here is correct, it is subject to change. This article was originally published on December 2, 2015. Last update: June 7, 2021.

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