SoftBank or Rakuten? Comparing Japan SIMs for Foreigners

Quick Answer

Rakuten Mobile is much cheaper (around ¥1,078–3,278/month tax included, automatically calculated based on your data usage) and offers free domestic calls through the Rakuten Link app, but its signal is weaker in rural areas, high-rise buildings, and basements. SoftBank is considerably more expensive (unlimited plans around ¥7,425/month before discounts) but has stable coverage almost everywhere and stores nationwide for in-person support.

In short: if you live in a big city, use a lot of data, and already have a Japanese bank account or credit card, Rakuten is the cost-saving choice. If you need reliable signal for work, travel to construction sites/mountainous areas, or want face-to-face support, SoftBank is the safer option.

But if you don't have a Japanese credit card yet, your Japanese isn't strong enough, or you're only staying in Japan for 1–2 years, both major carriers can be a hassle — in that case, a SIM/eSIM designed for foreigners (with Vietnamese support and no long-term contract) is usually more practical.

Who this article is for

This article is for you if:

• You're an international student, technical intern, engineer, specified skilled worker, or working professional living in Japan and about to choose a carrier.
• You're currently using a SIM and finding the bill too high, and want to know if switching to Rakuten is worth it.
• You've heard friends say "Rakuten is really cheap" but aren't sure what the real downsides are.
• You need a quick comparison of price, signal, paperwork requirements, and foreign-language support between these two carriers.

This article focuses on personal monthly phone SIMs used in Japan. If you need a short-term travel SIM or a portable WiFi device shared by the whole family, the selection process is different.

Cases where this does NOT apply

The information in this article does not apply if you fall into any of these categories:

• Staying in Japan for less than 3 months (tourism, short business trip): both SoftBank and Rakuten require valid residence documents and long-term contracts. You should use a prepaid travel SIM/eSIM instead.
• Your residence card is about to expire (less than about 3 months remaining): many carriers will refuse or only allow short-term contracts, depending on their policy at the time.
• You need a phone number today for a job application or paperwork: Rakuten's online registration may take a few days for the SIM to arrive by mail.
• You want to use a phone bought abroad that's SIM-locked: phones locked to a foreign carrier often won't pick up Japanese signal, so switching carriers won't help.
• You're comparing SIMs just for data use on a tablet, camera, or router: the plans from these two major carriers aren't optimized for this purpose.

Steps to take: how to choose between SoftBank and Rakuten?

Don't decide based on advertising. Follow these 6 steps, which take about 15 minutes.

1. Check how many GB you use per month. Go to your phone settings (Settings → Cellular → Data Usage) and check the last 1–2 months. Under 3GB, 3–20GB, or over 20GB will lead to completely different decisions.
2. Determine where you live and where you travel. If you only move around within Tokyo, Osaka, Nagoya, or Fukuoka, Rakuten's signal is now fine. If you work on a farm, construction site, mountain factory, or frequently ride trains through long tunnels, prioritize SoftBank.
3. Check if your phone is compatible. Rakuten requires a phone that supports its frequency bands and VoLTE. Rakuten's official website has a compatible device lookup — check your exact model before signing up.
4. Check if you already have a Japanese payment method. A Japanese credit card, debit card, or bank account for automatic withdrawal (口座振替). Without any of these, signing a contract with a major carrier will be very difficult.
5. Assess your Japanese language ability. The entire registration screen, confirmation messages, bills, and warning emails from Rakuten default to Japanese. If you can't read Japanese, the chance of signing up for the wrong plan or forgetting to cancel add-on services is very high.
6. Choose and sign up. Rakuten: register online or at a Rakuten Mobile store. SoftBank: register at a SoftBank store or online. If porting your number (MNP), get your MNP code (MNP One Stop now allows direct transfer without a code at many carriers) before starting.

Quick comparison table: SoftBank vs. Rakuten Mobile

Note: pricing and promotional conditions for both carriers change fairly frequently. The figures above are reference values at the time of source verification; you should confirm them on the official website before signing.

Don't forget SoftBank's sub-brands

Many people compare "SoftBank is expensive, Rakuten is cheap" while forgetting that SoftBank has two budget sub-brands that share the same network infrastructure:

• Y!mobile: Simple 2 plan is about ¥2,365 (4GB), ¥4,015 (30GB), ¥5,115 (35GB); can be reduced by ¥1,100–1,650/month with a family plan or home internet bundle. Has stores for in-person support.
• LINEMO: smaller plans around ¥990 (3GB) and about ¥2,090 (10GB), larger plan around ¥2,970 (30GB). Online support only, no physical stores.

This means if you want "SoftBank's signal at close to Rakuten's price," Y!mobile and LINEMO are worthwhile middle-ground options to consider.

Documents you need to prepare

Both carriers require identity verification (本人確認) as required by Japanese law. For foreigners, the typical document set includes:

• A valid Residence Card (在留カード) — this is the most important document. Some carriers require a minimum remaining validity period (usually about 3 months or more) for a standard contract.
• Passport (needed in some cases, especially when the name on the residence card is abbreviated or in a different order).
• A Japanese credit card, debit card, or bankbook + registered seal (inkan) for automatic payment registration. Credit cards issued overseas are often rejected.
• A current residential address matching your residence card (on the back of the card). If you've recently moved but haven't updated your registration at the ward/city office, your application may easily be rejected.
• An email address and a contact phone number to receive verification codes.
• An MNP code (if porting your number) or your previous carrier's information.

For online registration, you'll need to photograph both sides of your residence card and record/take a photo of your face following the instructions (eKYC). Blurry photos, glare, or a cut-off corner of the card are the most common reasons for rejection.

Costs

Estimated cost table for the first 12 months (tax included, not including device promotions):

The annual difference between SoftBank's main brand and Rakuten for heavy data users can reach about ¥45,000–50,000. This is why many foreigners switch to Rakuten. But remember to factor in the "hidden costs": days without signal when you need to call your company, or the time you'll spend figuring things out on your own when the system is only in Japanese.

Timeframes / Processing time

• In-store registration at SoftBank: about 1–2 hours if you have complete documents, usable the same day. Book ahead on weekends.
• Online registration with SoftBank: physical SIM usually arrives in 2–5 business days.
• Online registration with Rakuten (eSIM): if eKYC is approved, it can be usable within a few dozen minutes to a few hours. If asked for additional photos, it may take 1–2 days.
• Online registration with Rakuten (physical SIM): usually receive the SIM after 2–4 days.
• Number porting (MNP): the network switch usually completes within a few minutes to a few hours after activation.
• Contracts: both carriers now mostly have no 2-year lock-in and no cancellation fee, but if you're paying for a device in installments, the remaining installment balance stays even if you cancel the SIM.

Where to apply / where to go

SoftBank: SoftBank stores are present at most major stations and shopping centers. Some stores in areas with many foreign residents (Shinjuku, Shibuya, Ikebukuro, Shin-Okubo, Namba) have English- or Chinese-speaking staff; Vietnamese-speaking staff are rare. You can also register on the official website.

Rakuten Mobile: mainly online via the website or the my 楽天モバイル app. Rakuten Mobile stores exist in shopping centers and large electronics stores (Bic Camera, Yamada Denki), but there are fewer than SoftBank and foreign-language support is more limited.

LINEMO: online only, no physical stores. If you can't handle the process yourself, don't choose LINEMO.

Small tip: when visiting a store, bring your residence card, passport, bank card, and a fully charged phone. Going on a weekday morning is much faster than a Saturday afternoon.

Common mistakes

• Not checking if your phone is compatible with Rakuten. Phones bought in Vietnam or older devices sometimes can't pick up Rakuten's VoLTE, resulting in no calling ability even though there's data signal.
• Thinking calls on Rakuten are always free. They're only free when calling through the Rakuten Link app. If you dial from the default phone app, it's still charged at ¥22/30 seconds.
• Filling in a name that doesn't match the residence card. The order of last name–first name, spacing, and capitalization must exactly match the card, or eKYC will be rejected.
• Using a foreign credit card. Japanese carriers' payment systems often don't accept these, causing the contract to be canceled after the first month.
• Forgetting to cancel add-on services (オプション). Many promotional plans include free services for the first month, which automatically start charging a few hundred to over a thousand yen from the second month.
• Choosing SoftBank's unlimited plan but actually only using 5GB. Many people pay double what they need because they don't check their actual data usage.
• Canceling the old carrier before the new one is active. This results in losing the phone number or being unreachable for days. Always keep the old SIM until the new SIM is running smoothly.
• Moving without updating your address with the carrier. Notification letters, bills, and replacement SIMs won't reach you.

Frequently Asked Questions

Can foreigners newly arrived in Japan sign up for Rakuten?

Yes, if you have a valid residence card, an address registered at the ward/city office, and a Japanese payment method. The biggest obstacle usually isn't nationality but not yet having a Japanese credit card or bank account.

Is Rakuten's signal good now?

In major cities, it's good enough for daily work and entertainment, and has improved significantly since Rakuten added the 700MHz band. However, in concrete buildings, basements, mountainous areas, and on some train lines, SoftBank is still noticeably more stable.

If I switch from SoftBank to Rakuten, can I keep my old number?

Yes. You use the number porting (MNP) procedure. In many cases now, you can transfer directly without needing to request a code beforehand. Note that an email address ending in @softbank.ne.jp will be lost unless you sign up for an email retention service.

I'm using SoftBank — should I switch to Y!mobile instead of Rakuten?

If you're happy with the signal but not the price, Y!mobile is a safe transition: same SoftBank signal, about half the price, and stores are still available for support. Switching to Rakuten saves more money but you have to accept the signal risk.

Which one should I choose if I don't know Japanese?

Neither carrier has reliable Vietnamese support. In this case, a SIM designed specifically for foreigners with Vietnamese-speaking staff is usually less risky: you'll clearly understand what you're signing up for and won't be charged unexpected fees.

I'm only staying in Japan for 1 year — should I sign a contract with a major carrier?

Not necessary. You should choose a prepaid plan or a month-to-month plan with no lock-in, so that when you leave the country you won't have to go through complicated cancellation procedures in Japanese, and won't worry about automatic charges after you've already left Japan.

Does Rakuten have eSIM, and can I use it on an iPhone?

Yes. Rakuten issues eSIM fairly quickly via the app and supports many recent iPhone models. Still, you should check your exact model on the official website before signing up.

References

• Rakuten Mobile — Rakuten Saikyou Plan pricing and compatible device list: network.mobile.rakuten.co.jp
• SoftBank — official mobile pricing page: softbank.jp/mobile
• Y!mobile — Simple 2 plan: ymobile.jp
• LINEMO — official plan pricing: linemo.jp
• Japan's Ministry of Internal Affairs and Communications (総務省) — regulations on identity verification when signing telecom contracts: soumu.go.jp

Pricing, promotions, and identity verification requirements may change at any time. Before signing a contract, you should check directly on the carrier's official website or ask store staff. For issues related to your residence card's validity period, please confirm with the Immigration Services Agency (出入国在留管理庁) or your local ward/city office.

Source verification date

The content was cross-checked against the official pages listed above on May 20, 2025. If you're reading this article a long time after that date, please check the latest pricing.

Still not sure? HD TELECOM can help

SoftBank suits people who need reliable signal and in-person support. Rakuten suits people who want to save money and can manage on their own in Japanese. But if you fall in between — no Japanese credit card yet, limited Japanese ability, or only staying in Japan for a few years — a simple, clearly priced SIM with Vietnamese-speaking support will make things much easier.

HD TELECOM (office in Shin-Okubo, Tokyo) specializes in serving foreigners living and working in Japan:

• Monthly data SIM — no long-term commitment, suitable for international students and newcomers.
• 12-month prepaid SIM — pay once, no worrying about monthly bills.
• Monthly eSIM — get the code and start using it right away, no need to wait for a SIM to arrive.
• Voice call SIM with a Japanese phone number for job applications, opening accounts, registering for services — see more at the registration page.
• Monthly portable WiFi if your whole family or dorm room wants to share.

See all options on the product page, or visit the support page to learn about payment and bank transfer methods. Feel free to ask us anything in Vietnamese — we'll tell you straightforwardly which plan suits you, even if the answer is that you don't need to switch SIMs.