Ubigi is an eSIM brand of Transatel, part of the NTT group, selling data plans for more than 200 destinations. For Japan it lists all three major networks (docomo, KDDI and SoftBank), and its plans start counting days only when you arrive.
Our verdict: a flexible, fairly priced pick if you want days to start on arrival, hotspot use allowed and an eSIM you can reuse in other countries. 10GB for 30 days is US$16.50. Recent traveller reports of data dropping out in Tokyo mean it’s worth keeping a backup.
Who it suits, and who should skip it
Good fit if you:
- want a data-only eSIM you can install before you fly, with days counting from arrival
- travel often: the same Ubigi eSIM can be reused and topped up for other destinations in its app
- need to share data: Ubigi says data sharing (hotspot) is allowed
Look elsewhere if you:
- need a Japanese phone number: see getting a Japanese phone number
- can’t afford a day without data: several travellers reported Ubigi losing data in Tokyo while still showing full signal
Plans and prices
Ubigi’s Japan page only shows its 1GB plan, but every plan has its own page on Ubigi’s site, and these are the prices shown there in US dollars. Visitors browsing from some countries see euros instead. Ubigi doesn’t show yen.
One-off plans (no renewal):
| Plan | Phone number | Hotspot | Checked | Link | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Ubigi docomo au (KDDI) SoftBank | 10GB, 30 days eSIM | 10GB | 30 | $16.50 | ≈$0.55 | ≈$1.65 | No | Yes | Checked | View deal |
| Ubigi docomo au (KDDI) SoftBank | 5GB, 15 days eSIM | 5GB | 15 | $10 | ≈$0.67 | ≈$2.00 | No | Yes | Checked | View deal |
| Ubigi docomo au (KDDI) SoftBank | 25GB, 30 days eSIM | 25GB | 30 | $32 | ≈$1.07 | ≈$1.28 | No | Yes | Checked | View deal |
| Ubigi docomo au (KDDI) SoftBank | 1GB, 3 days eSIM Days count from arrival in Japan. | 1GB | 3 | $3.50 | ≈$1.17 | ≈$3.50 | No | Yes | Checked | View deal |
| Ubigi docomo au (KDDI) SoftBank | 50GB, 30 days eSIM | 50GB | 30 | $55 | ≈$1.83 | ≈$1.10 | No | Yes | Checked | View deal |
| Ubigi docomo au (KDDI) SoftBank | 10GB, 7 days eSIM | 10GB | 7 | $14 | ≈$2.00 | ≈$1.40 | No | Yes | Checked | View deal |
| Ubigi docomo au (KDDI) SoftBank | Unlimited, 30 days eSIM 60GB at full speed, then 2 Mbps. | Unlimited | 30 | $65 | ≈$2.17 | – | No | Yes | Checked | View deal |
| Ubigi docomo au (KDDI) SoftBank | Unlimited, 15 days eSIM 30GB at full speed, then 2 Mbps. | Unlimited | 15 | $39 | ≈$2.60 | – | No | Yes | Checked | View deal |
| Ubigi docomo au (KDDI) SoftBank | Unlimited, 8 days eSIM Full speed for 5GB a day, then 2 Mbps until the day resets. | Unlimited | 8 | $25 | ≈$3.13 | – | No | Yes | Checked | View deal |
Per-day and per-GB figures are approximate, converted to US dollars at the European Central Bank rate of 19 Oct 2026. Prices are in the currency each provider’s site showed us, so you may see a different currency. You pay the provider’s checkout price. Per GB is left blank for unlimited and daily-allowance plans.
Monthly plans renew every month, are bought in the Ubigi app and can be cancelled after three months. Ubigi also sells 5GB a month for 12 months as one payment of US$55.
| Plan | Phone number | Hotspot | Checked | Link | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Ubigi docomo au (KDDI) SoftBank | 5GB a month eSIM Renews every month. Bought in the Ubigi app; can be cancelled after three months. | 5GB | Monthly | $8/month | ≈$0.27 | ≈$1.60 | No | Yes | Checked | View deal |
| Ubigi docomo au (KDDI) SoftBank | 20GB a month eSIM Renews every month. Bought in the Ubigi app; can be cancelled after three months. | 20GB | Monthly | $18/month | ≈$0.60 | ≈$0.90 | No | Yes | Checked | View deal |
| Ubigi docomo au (KDDI) SoftBank | Unlimited a month eSIM 60GB at full speed, then 2 Mbps. Renews every month. Bought in the Ubigi app; can be cancelled after three months. | Unlimited | Monthly | $45/month | ≈$1.50 | – | No | Yes | Checked | View deal |
Per-day and per-GB figures are approximate, converted to US dollars at the European Central Bank rate of 19 Oct 2026. Prices are in the currency each provider’s site showed us, so you may see a different currency. You pay the provider’s checkout price. Per GB is left blank for unlimited and daily-allowance plans.
Key details
- Networks: Ubigi lists KDDI, NTT docomo and SoftBank for Japan.
- Unlimited plans: each has a full-speed allowance, then slows to 2 Mbps. On the 8-day plan that’s 5GB a day, resetting every 24 hours from when you first activated it. The 15-day plan gets 30GB in total and the 30-day plan 60GB.
- Hotspot: allowed. Ubigi says “data sharing allowed” on every Japan plan.
- Phone number: none. Ubigi is data only; use WhatsApp, LINE and similar apps for calls.
- When the days start: when you arrive in Japan (Ubigi calls this Smartstart). Plans not activated within six months of purchase expire.
- Top-ups: in the Ubigi app, which Ubigi says works even without WiFi or remaining data. The same eSIM can be reused in 200+ destinations.
- Support: Ubigi says its contact form is the best way to reach its support team, especially for account problems. There’s also an automated chat on its website, and a WhatsApp line answered by an AI assistant that can’t see your account.
- Phones: needs an unlocked, eSIM-compatible phone. It also works on some Windows 10 and 11 laptops.
- How to buy: one-off plans on the website (the QR code arrives by email) or in the app. Monthly plans are sold in the app.
How it performed in Osaka
Hands-on test results
Speed, activation time and coverage results for Ubigi aren’t published yet. Until they are, nothing on this page claims first-hand testing. How we test
What other travellers report
We haven’t tested Ubigi ourselves yet, so this is what we found in traveller reports on Reddit and X, not our own results.
- Plenty of good trips. Several travellers on X say setup was easy and it worked well across Japan. One independent tester found it the quickest of three eSIMs in Tokyo and Kyoto in June 2026.
- But a run of “no data” reports. Several travellers on Reddit in 2026 described full signal in Tokyo with no working data, or sudden “no service” with data still left. Similar reports turned up on X in 2024.
- Support gets mixed reviews. Some Reddit posts in 2026 called it unhelpful. Ubigi says its contact form is the way to reach a person, since its WhatsApp line is an AI assistant.
Pros and cons
Pros
- Lists docomo, KDDI and SoftBank for Japan
- Days count from arrival, not from installation
- Hotspot use allowed
- One reusable eSIM for 200+ destinations, topped up in the app
- Fixed-data prices that compete with the cheapest: 10GB for 30 days is US$16.50
Cons
- Several recent reports of data stopping in Tokyo while the phone still shows signal
- Unlimited plans slow to 2 Mbps after a full-speed allowance: 5GB a day on the 8-day plan, 30GB in total on 15 days
- Ubigi’s Japan page only shows the 1GB plan; the others are on separate pages or in the app, so they’re easy to miss
- Prices are in US dollars or euros, not yen
- Data only, with no Japanese phone number
Questions people ask
How much does Ubigi cost for Japan?
From US$3.50 for 1GB over 3 days. A week of moderate use is US$14 for 10GB over 7 days, and unlimited starts at US$25 for 8 days. See the tables above for every plan, with the date we checked it.
How good is Ubigi in Japan?
We haven’t run Ubigi through our Osaka test route yet, and results will appear above when we have. On paper it’s well set up for Japan: it lists all three major networks, allows hotspot use and starts counting days when you arrive. Traveller reports are mostly positive, but several from Tokyo in 2026 describe data stopping while the phone showed full signal.
Which network does Ubigi use in Japan?
Ubigi lists KDDI, NTT docomo and SoftBank for Japan.
Is Ubigi’s unlimited plan really unlimited?
Not at full speed. The 8-day plan gives 5GB a day at full speed, and the 15 and 30-day plans give 30GB and 60GB in total. After that, speed drops to 2 Mbps, according to Ubigi.
What is the Ubigi app?
It’s where you manage your Ubigi eSIM: check your balance and buy top-ups, even without WiFi or remaining data, according to Ubigi. Monthly plans are sold there too.
Alternatives
Compare Ubigi with every other Japan eSIM in our best eSIMs for Japan guide, or see our Airalo review.
