Prepaid Japan SIM Card Review: eConnect Japan, b-mobile & More!


Last updated: 12/14/2015

When it comes to traveling in Japan it seems the best option these days for data is renting a SIM card. In this article we’ve done the hard work for you by comparing today’s top prepaid Japan SIM card rentals, including eConnect, cdJapan, b-mobile, and more, and let you know who is providing the best deal.

Japan SIM Rental

What we cover:

Best Prepaid Japan SIM Card: Fixed Data Plans

(Green = Best Value)


(no longer available)

eConnect Japan

Sakura Mobile

Service Provider NTT Docomo NTT Docomo NTT Docomo
Price per GB ¥2,380 ¥1,496–3,480 ¥785–1,165
One-Time Fee ¥790 ¥890
Daily Rental Fee ¥50
Top Up 1GB = ¥2,380 Available; price unknown 1GB = ¥750–1,500
Delivery Mail / Retail Mail Mail
Expiration 14 Days 7–30 Days 45 Days
Data Speed Up to 150mbps Up to 150mbps (possible throttling) Up to 150mbps
SIM Size Nano / Micro / Standard Nano / Micro / Standard Nano + adapter
Skype Friendly Yes Depends on plan Yes

Best Prepaid Japan SIM Card: Unlimited Data Plans

(Green = Best Value)





Service Provider NTT Docomo NTT Docomo NTT Docomo Softbank
Device Limitation iPhone 4,5,6 / Android iPhone
One-Time Fee ¥2,380 ¥540 ¥315
Daily Rental Fee ¥328 ¥1,140–1,715
Depending on device
Top Up ¥2,204 (additional 14 days) ¥133 / day
Delivery Mail / Retail Mail Airport Pick-up Airport Pick-up
& Select SoftBank Shops
Expiration 14 Days
Data Speed Up to 300kbps 128kbps after 110MB/Day Unknown Unknown
SIM Size Nano / Micro / Standard Nano / Micro / Standard Unknown Unknown
Skype Friendly No No Unknown Unknown

Considerations when comparing SIM cards

When considering prepaid Japan SIM card companies, three main factors were considered: the data network, the data type (fixed or unlimited), and overall value.

Japanese Network Providers

Of the six companies compared, only two of the three major Japanese carriers were available: NTT Docomo and Softbank. If you want to understand more about the benefits of each carrier, here’s an interesting article by Sakura Mobile on comparing Japanese service providers.

Unlimited or Fixed Data Plans

There are two options when renting a SIM card in Japan—unlimited data or fixed data (e.g., 3GB, 5GB, etc.). Both types have their benefits, which boil down to unlimited plans guaranteeing service throughout your contract (albeit often at a snail speed) and fixed data plans offering higher speeds with the option to top up when you start reaching your limit.

Plan Value

The biggest factor to consider is which SIM rental provides the best value. Because each company offers different plan structures, the best way to accurately compare this factor was to calculate price per GB for the fixed data plans and price per day for the unlimited plans.

Other Considerations

Other factors to consider include:

  • Delivery system (mail or retail stores)
  • Plan expiration
  • SIM card size (nano, micro, standard)
  • VoIP capability (Skype)

You can skip to our conclusion if you interested in knowing which Japanese SIM Card rental we recommend.

Sakura Mobile

best japan sim card

Sakura Mobile provides rental SIM cards based on a fixed data system as well as a long-term stay plan that is quite affordable if staying in Japan for more than a month.  They are a certified wireless provider that operates on the NTT Docomo network, Japan’s largest 4G LTE cellular network that covers 99% of the population, and offer rental SIM cards that require no activation, support VoIP calling, and no data throttling. Offering flexible data plans starting at 3GB for 3500 yen plus a small daily rental fee.


cdjapan sim card

cdJapan offers prepaid Japan SIM card rentals on the NTT Docomo network.  They can be rented for a minimum of 5 days at 340 yen a day with discounts on that rate depending on the rental period.  Please note, that with cdJapan, your download speed will be throttled to 200 kbps after you exceed 110 MB of data usage in a single day.



b-mobile offers pre-paid SIM cards that work on the NTT Docomo network.  They offer two types of services, both of which are relatively limited in nature.  They have a 1GB data plan or a 14-day visitor plan that has unlimited data allowances but data speeds are capped at 300 kbps so this option may not be suitable for calls using VoIP applications or other streaming content.  b-mobile charges a flat 3,686 for its SIM cards (regardless of plan).

eConnect Japan

econnect japan

With eConnect Japan, prepaid SIM cards can be ordered either in fixed data allowances of 1–3GB or else fixed time periods of 7–30 days with 100MB of data per day.  Rates range from 2,800–4,700 yen.  Either service type comes with a 790 yen shipping fee.

SoftBank Global Rental

softbank sim card

Softbank, one of the major cellular network providers in Japan, offers rental SIMs for the iPhone 3–6 Plus, though note that it’s only for versions that work on its network.  It offers an unlimited data plan at 1,550 yen per day plus rental and administrative fees.  SIM cards are only available at the Softbank counters at airports.  Also, please note that your iPhone must be compliant with Japan’s “Conformity Certification of Radio Equipment” in order to use this service.  Also, note that this service is not available for Android.

Global Advanced Communications (GAC)

gac sim card

GAC offers rental SIM cards that operate on the NTT Docomo network and are compatible with both iPhones and Android phones.  GAC plans offer unlimited data usage and 1000 yen worth of free local calls.  Their plan rates are based on days of use and start at rates ranging from 7,000–12,000 yen depending on the type of phone and minimum number of days in the rental period.  SIM cards must be picked up at the airport upon arrival and cannot be delivered to a hotel or other address.

Which prepaid Japan SIM Card offers the best deal?

If you’re a mid-to-heavy data user, then it’s likely that the most cost-effective prepaid Japan SIM card option for you is one with a fixed data allowance, which is generally much cheaper and more flexible in terms of when and how they can be used.

When comparing fixed data competitors, Sakura Mobile come out as the cheapest option per GB, the cheapest option for top up, the fastest data speed, and longest set expiration terms (available at 45 days, which can come in handy in case you love Japan so much you want to stay just a bit longer), and their SIM cards support VoIP. At 600–1000 yen a day, you can get guaranteed strong data speeds and wide coverage throughout Japan.

best japan sim card

It’s a little bit tougher to directly compare fixed data plans with unlimited plans, but what is important to point out is that while unlimited always sounds nice on paper, most companies offering this option either don’t state directly on their websites what data speed you will get with the rental, or when they do, the speed is significantly slower than the fixed data options. With that being said, if you’re heading to Japan on a strict, barebones budget and need to use your phone only incases of an emergency, then a minimal data plan like cdjapan could work for you.

cdjapan sim card

Related posts:


    • admin says

      There are 2 types of SIM card rentals to consider: Pay as you go (fixed data) and Unlimited. b-mobile is a popular option for tourists and at one point offered both types of plans. Based on our last check, though, they currently only offer the 14-Day unlimited plan. This is why the pay-as-you-go plan is marked as “no longer available”.

  1. Mika says

    Recently I backed to Japan for a month and I was told buy prepay a card which best option rather than roarming by 2 degree NZ but while in Japan,I tried prepay card or buying sim card or somehow connect my mob to use my mobile phone was so frustrated because all major communication companies AU,Softbank,Docomo said to me need 2 years contract so I couldn’t use my mob at all during I was in Japan Japan and even if sign contract ,will be charged penalty heaps,Can you tell me what is best option for next time go back to Japan and I could use my mobile without worry and frustrated?

    • admin says

      There are several SIM resellers currently in Japan that offer contract-free SIM options for overseas tourists. However, if you’re concerned that a SIM rental won’t work with your phone (and for many tourists, it doesn’t), then we suggest renting a Pocket WiFi Router. It performs the same as a data SIM card (this means you can connect to the Internet but can’t make a standard phone call), but is much more simple to set up and use. The major downsides to pocket WiFi routers are that 1) you have to carry another device with you on your trip and 2) battery life.

  2. Jann says

    Hi, I am interested in getting a mobile phone & line / Sim card for a foreigner working in Japan for at least 3 mths and may extend the line after.
    Please revert asap via email please.

    Thank you.

Leave a Reply

Your email address will not be published. Required fields are marked *