Last verified: February 2, 2026 (JST)
If you've searched for mobile plans in Japan, you've probably seen "ahamo" pop up everywhere. But what exactly is it? Is it good for foreigners? Can you use it in English? This complete guide answers all your questions with verified, up-to-date information as of 2026.
What is ahamo?
ahamo is NTT Docomo's online-only mobile service launched as a low-cost option that operates on Japan's largest and most reliable cellular network. Think of it as Docomo's budget-friendly brand—you get the same excellent network quality but with a simpler, digital-first approach.
Operator: NTT DOCOMO, INC. (Japan's flagship carrier with the broadest nationwide coverage)
Key Point: ahamo runs on Docomo's main network infrastructure, not as an MVNO (Mobile Virtual Network Operator). This means you get full 4G/5G speeds and premium network quality at a fraction of the cost.
Current Plans & Pricing (2026)
ahamo keeps its pricing structure refreshingly simple with just two main options. The base plan offers a solid middle ground for most users, while the large data option caters to heavy data consumers who stream video content regularly or use their phone as a mobile hotspot.
Base Plan
The standard ahamo plan gives you 30GB of data for ¥2,970 per month (tax included)—a notable increase from the original 20GB offering in previous years. This plan includes the first 5 minutes free on every domestic call you make, which is perfect for quick check-ins, restaurant reservations, or confirming appointments. After those initial 5 minutes, calls cost ¥22 per 30 seconds.
Large Data Plan (Oomori Option)
For users who need significantly more data, the Oomori option provides a massive 110GB (combining the 30GB base with an additional 80GB add-on) for ¥4,950 per month (tax included). You still get the same 5-minute free calling benefit, making this an exceptional value if you regularly exceed 30GB or use your phone to tether laptops and tablets.
Optional Add-ons
Beyond the core plans, ahamo offers two straightforward add-ons. If you make frequent or long calls, you can add unlimited domestic calling for an extra ¥1,100 per month. And if you occasionally burn through your data allowance before the month ends, you can purchase additional 1GB blocks at ¥550 each to restore your full-speed connection.
Data Allowances & What Happens When You Run Out
In Japan
When you exceed your monthly data limit—whether that's 30GB on the base plan or 110GB on the large plan—ahamo throttles your speed to 1Mbps. While that might sound restrictive, 1Mbps is actually quite usable for everyday tasks. You can still use LINE for messaging and voice calls, browse social media without much frustration, and even watch YouTube at 360p resolution. This is notably faster than many competitors who throttle all the way down to 128Kbps or 300Kbps, speeds that make even basic browsing feel painfully slow.
Your data allowance resets automatically at midnight on the 1st of each month, giving you a fresh start. If you can't wait until then, those ¥550 per 1GB add-ons can tide you over for urgent needs.
International Roaming (Major Advantage!)
Here's where ahamo truly shines: you get free data in 91 countries and territories with no extra charge and no advance registration required. Just land in your destination country, turn on your phone, and you're connected. The service automatically works in popular destinations including the USA, Hawaii, Guam, Thailand, Singapore, UK, Italy, France, Germany, Taiwan, South Korea, and most of Europe and Southeast Asia.
However, there are some important limitations to understand. Regardless of which plan you have (30GB or 110GB in Japan), you're capped at 30GB maximum for overseas data usage. Additionally, ahamo enforces a 15-day rule: after 15 consecutive days abroad, your speed drops to a crawl at 128Kbps until you return to Japan. This means ahamo works beautifully for frequent short trips or week-long vacations, but it's not designed for digital nomads or extended stays abroad.
English Support: The Reality
Here's the biggest challenge for non-Japanese speakers: ahamo offers virtually no English support throughout the entire customer experience. From the initial signup to troubleshooting technical issues, every interaction happens exclusively in Japanese.
The website (https://ahamo.com/) displays entirely in Japanese with no English language option. Customer service operates solely through online chat—there's no phone support at all, even for Japanese speakers—and that chat is Japanese-only. The application process requires navigating a completely Japanese interface, and there's no bilingual documentation or support materials available through the ahamo platform itself.
While NTT Docomo (ahamo's parent company) does provide some English informational pages about their services, these are general overviews. When it comes to actually using ahamo—signing up, managing your account, troubleshooting issues, or contacting support—you're entirely on your own if you can't read and communicate in Japanese.
Support channels available:
- Website: Japanese only (https://ahamo.com/)
- Customer service: Online chat in Japanese only
- Application: Entirely Japanese interface
- Phone support: Not available (chat only)
Limited English Documentation
The disconnect between Docomo's English information pages and ahamo's Japanese-only reality creates a false impression for some foreign residents. You might read about ahamo in English on Docomo's corporate site, but once you try to actually sign up or use the service, everything switches to Japanese.
Bottom Line for Foreigners: ahamo is realistically only suitable for Japanese-speaking foreigners, or for non-Japanese speakers who have Japanese-speaking friends or partners who can assist with setup and ongoing troubleshooting. If you need English support for your mobile service, consider LINEMO (which offers English signup) or Rakuten Mobile (full English website and support).
How to Sign Up (Requirements for Foreigners)
Signing up for ahamo requires navigating several specific requirements that can be challenging for foreigners, particularly if you don't read Japanese. The entire application process happens online through ahamo's Japanese-language website—you cannot walk into a Docomo store and sign up there. If you need in-person assistance at a physical Docomo shop, you'll pay a ¥3,300 store assistance fee, and even then, you'll still need to complete the actual online application yourself.
What You Need to Apply
Essential documents:
- Residence Card (在留カード) - Absolutely mandatory. Tourists cannot sign up.
- Visa Status: Your visa must be valid for longer than 90 days from the application date
- d Account: You'll need to create a Docomo "d account" first (this process is also in Japanese)
Payment Method Requirements
Payment is one of the trickier aspects. ahamo requires either a Japanese credit card (where the cardholder's name must exactly match the contract holder's name) or a Japanese bank account like Japan Post Bank (ゆうちょ銀行). Foreign credit cards are frequently rejected, even if they're Visa or Mastercard. The system requires 3D Secure 2.0 authentication, which many international cards don't support. Japanese credit cards are strongly recommended to avoid payment verification headaches.
Identity Verification Process
ahamo uses eKYC (electronic Know Your Customer) for identity verification. You'll upload photos of your Residence Card and complete a face photo verification process. This typically takes a few hours to 1-2 days for approval, though some applications process faster.
SIM Delivery Options
Once approved, you have two options:
- Physical SIM: Ships in approximately 3 days via mail
- eSIM: Immediate activation after approval (for compatible devices)
Many non-permanent residents report that their eSIM applications get rejected based on visa status, even when physical SIM applications would be approved. If you're on a student visa or shorter-term work visa, you may need to opt for the physical SIM instead.
Key Features
Beyond the basics of data and calling, ahamo includes several features that add value to your service. The plan provides full 4G/5G access on Docomo's network with no extra charge for 5G connectivity. If you have a 5G-capable phone, you can optionally enable 5G SA (Standalone) for potentially faster speeds in areas where this advanced network technology is deployed.
Tethering and mobile hotspot functionality come included at no additional cost, using data from your main allowance. This means you can share your phone's internet connection with your laptop, tablet, or other devices whenever you need—perfect for working at a café or sharing your connection with travel companions.
On the contract front, ahamo offers flexibility that was rare in Japan's mobile market until recently. There's no minimum contract period, so you're not locked into a year or two of service. The cancellation fee policy has evolved significantly: contracts started on or after July 1, 2025 have no cancellation fee whatsoever. For older contracts from before that date, there's a ¥1,100 fee only if you cancel within the first year and the service determines your usage pattern suggests resale activity rather than personal use. As of 2026, most active users face zero cancellation fees.
Number portability (MNP) is fully supported if you want to keep your existing Japanese phone number when switching to ahamo. And if you use multiple phone numbers or want to keep your home country number active, ahamo supports dual SIM configurations with both nano SIM and eSIM, allowing you to run multiple eSIMs simultaneously on compatible devices.
Pros & Cons for Foreigners
Network Quality and Coverage
The most compelling reason to choose ahamo is the underlying network quality. As a Docomo service, ahamo operates on Japan's most extensive cellular network, with 99%+ nationwide coverage that extends far beyond major cities. Where ahamo particularly excels is rural coverage—the network reaches into countryside areas, mountains, and small towns where other carriers often struggle. You'll maintain reliable connections in most buildings and subway systems throughout Japan. This premium network quality at a mid-range price point is ahamo's fundamental value proposition.
International Roaming Benefits
For frequent international travelers, ahamo's free data roaming across 91 countries is genuinely exceptional. The 30GB of overseas data comes included in your plan at no extra charge, with no advance registration paperwork to file. This feature alone can save you hundreds of yen per trip compared to competitors who charge for international data or force you to purchase separate roaming packages.
Pricing and Flexibility
At ¥2,970 for 30GB or ¥4,950 for 110GB, ahamo's pricing is competitive within the Japanese market, especially considering you're getting premium Docomo network quality. There are no hidden fees or surprise charges—what you see is what you pay. The no-contract-lock-in approach means you can cancel anytime without penalty (in most cases), and the included tethering means you're not paying extra to share your connection with other devices.
Even when you exceed your data limit, ahamo's 1Mbps throttled speed remains usable for basic tasks—a significant advantage over competitors who throttle down to near-unusable 128Kbps or 300Kbps speeds.
Language Barrier Challenges
The overwhelming disadvantage for non-Japanese speakers is the complete absence of English support. The entire website, mobile app, customer service system, and account management interface operates exclusively in Japanese. Because ahamo only offers online chat support (no phone support even in Japanese), troubleshooting becomes particularly difficult if you encounter technical problems and can't communicate effectively in written Japanese.
Application and Payment Hurdles
The signup process presents multiple potential friction points. You must navigate the entirely Japanese-language application, which is intimidating if you're not comfortable reading Japanese. Credit card payment acceptance can be problematic—foreign credit cards are frequently rejected even from major networks, and some users report that certain card types aren't supported at all. eSIM applications often get denied for non-permanent residents, forcing you to use physical SIM cards instead.
Network Congestion and International Limits
In extremely crowded situations like major festivals, concerts, or sporting events, Docomo's network can experience congestion and slowdowns—an inevitable consequence of being Japan's largest carrier with the most users. For international use, the 15-day consecutive overseas stay limit is a hard constraint. If you're abroad for longer than two weeks straight, your speed drops to barely-usable 128Kbps until you physically return to Japan, making ahamo unsuitable for extended international trips or remote work abroad.
Is ahamo Right for You?
ahamo makes the most sense for foreigners who speak Japanese or have reliable Japanese-language support and who travel internationally 2-3 or more times per year. The combination of premium Docomo network quality and free international roaming creates exceptional value for this use case. If you need reliable coverage in rural areas of Japan—perhaps you live outside major cities or regularly travel to countryside locations—ahamo's Docomo network provides connectivity that other budget carriers simply can't match.
The service is also ideal if you consistently use 30GB or more of data each month and value network quality over cost savings, or if you make frequent short domestic calls that benefit from the included 5-minute free calling. Essentially, ahamo works best for users who understand Japanese and whose usage patterns align with the service's strengths in network quality and international features.
On the other hand, ahamo becomes a poor choice if you don't speak Japanese and lack ongoing support for troubleshooting. Without reliable English customer service, even simple account changes or technical issues become major obstacles. If you need English-language customer service, stay primarily in urban areas (where LINEMO or povo offer similar coverage), rarely travel internationally (wasting ahamo's best feature), or use less than 20GB of data per month (Rakuten Mobile or LINEMO may cost you less), then other carriers will likely serve you better.
Quick decision guide:
✅ Choose ahamo if you:
- Speak Japanese or have Japanese-speaking support
- Travel internationally 2-3+ times per year
- Need reliable rural coverage
- Want 30GB+ data consistently
- Value network quality over English support
- Make frequent short calls (5-min included)
❌ Skip ahamo if you:
- Don't speak Japanese and lack support
- Need English customer service
- Stay in urban areas only
- Rarely travel internationally
- Use less than 20GB/month
Comparison with Alternatives
| Feature | ahamo | Rakuten Mobile | LINEMO |
|---|---|---|---|
| English Support | ❌ None | ✅ Full | ⚠️ Limited |
| Cheapest Plan | ¥2,970 (30GB) | ¥1,078 (0-3GB) | ¥990 (3GB) |
| Free Int'l Roaming | ✅ 91 countries | ⚠️ 2GB/month | ❌ Paid |
| Network Quality | ⭐⭐⭐⭐⭐ | ⭐⭐⭐ | ⭐⭐⭐⭐⭐ |
| Rural Coverage | Excellent | Fair | Excellent |
| Application | Japanese only | English available | English available |
For detailed comparisons: See our ahamo vs povo vs LINEMO comparison or Rakuten Mobile vs major carriers.
How to Apply with English Help
Since ahamo has no English support, here are your options:
- Use a translation tool like Google Translate with camera function to photograph each page of the Japanese application
- Ask a Japanese-speaking friend or partner to help with signup and save their contact for future troubleshooting
- Visit a Docomo store (pay ¥3,300 assistance fee, though you'll still complete the application online)
- Choose an English-friendly alternative like Rakuten Mobile with full English support or LINEMO with English signup
Frequently Asked Questions
Q: Can I use ahamo without speaking Japanese? A: Technically yes if you have help during signup and reliable ongoing support for troubleshooting, but managing your service, interpreting bills, and handling technical issues will be challenging. It's not recommended unless you have a Japanese-speaking friend or partner who can assist whenever problems arise.
Q: Does ahamo work with my iPhone? A: Yes, ahamo supports most modern smartphones including iPhone XR and newer models. eSIM is available for compatible devices, though non-permanent residents sometimes face eSIM approval issues.
Q: How long does activation take? A: Physical SIM cards arrive in approximately 3 days via mail. eSIM activates within a few hours after your application is approved.
Q: Can I keep my current Japanese phone number? A: Yes, through MNP (Mobile Number Portability). The process is available via MNP One-Stop (simplified method) or the traditional two-step method.
Q: What happens if I exceed 30GB in Japan? A: Your speed drops to 1Mbps, which is still usable for messaging, social media, and lower-quality video streaming. You can purchase 1GB add-ons at ¥550 each to restore full speed before your monthly reset.
Conclusion
ahamo offers excellent network quality, competitive pricing, and unbeatable international roaming—but only if you can navigate the Japanese-only interface and support system. The service delivers genuine value for its price point, particularly for users who travel internationally and need reliable coverage throughout Japan.
For English-speaking foreigners: Unless you have reliable Japanese language support, consider these alternatives:
- Rakuten Mobile SAIKYO Plan - Full English support, starting at ¥1,078/month
- LINEMO - English signup, LINE data-free, ¥990-¥2,970/month
- Compare all options - See which plan fits your needs
Ready to get started? If ahamo isn't right for you, check out Rakuten Mobile with English support and up to ¥14,000 referral benefits →