Every "best eSIM for Japan" list you'll find says roughly the same thing: buy an eSIM, it's cheaper than a pocket Wi-Fi, done. That's true, but it skips the part that actually costs you money or signal — the four big travel eSIM providers for Japan don't all run on the same network, don't all let you keep your data if you want to switch mid-trip, and one of them doesn't sell data-only plans at all. We checked prices and plan terms for Airalo, Ubigi, Holafly and Sakura Mobile in October 2026 and compared them side by side so you can pick once and not think about it again.
Chopi: Why would the network matter? Isn't Japan small enough that any of them works everywhere?
Log: Mostly, yes — in Tokyo, Osaka, Kyoto you won't notice a difference. It starts to matter on remote islands, mountain trails, or anywhere outside a big city, which is exactly where we spend a lot of our time.
What actually differs between Japan travel eSIMs
Strip away the marketing and four things separate these plans:
- Which Japanese network it rides on. There's no such thing as a neutral "eSIM network" — every travel eSIM reseller buys wholesale access to NTT Docomo, KDDI (au), or SoftBank's physical towers. Docomo has the widest rural and mountain reach of the three; SoftBank and au are strongest in cities and roughly tied outside them.
- Fixed data vs. unlimited with a hidden cap. A "20GB" plan is a real, checkable number. An "unlimited" plan almost always has an undisclosed fair-use threshold after which your speed gets throttled — the providers that sell unlimited don't publish the number.
- Data-only vs. a real Japanese phone number. Most travel eSIMs are data-only — no number, so you can't receive an SMS verification code from a Japanese store or make a normal phone call to a restaurant. Only one of the four we checked sells a plan with an actual +81 number attached.
- What happens if you want to switch. Once an eSIM profile is installed, deleting it to try a different provider is permanent — you can't put the same QR code back in. Decide before you fly; don't plan to test two mid-trip.
The four we checked
Airalo (sold under the "Moshi Moshi" plan name for Japan)
Airalo is the price leader. As of October 9, 2026 its fixed-data tiers for Japan ran from 1GB/3 days at $4.00 up to 20GB/30 days at $25.00, plus unlimited options from $11.50 for 3 days. It's data-only — no phone number, no SMS. Airalo's Japan eSIM rides on SoftBank and KDDI (au); it does not include Docomo, so coverage in deep countryside, small islands, or mountain areas can be weaker than a Docomo-backed plan. For a trip that's mostly Tokyo, Osaka, Kyoto and the shinkansen between them, that gap won't show up.
Ubigi
Ubigi is the only major travel eSIM we found running on NTT Docomo (alongside KDDI), which is the detail that matters if your trip includes somewhere rural — the Japan Alps, Hokkaido's countryside, or an outer island like Okinawa's Miyako or Ishigaki. Its one-time plans for Japan ran $25 for 8 days, $39 for 15 days and $65 for 30 days of unlimited data, with smaller fixed tiers from $8/month for 5GB. Data-only, same as Airalo, but the rural coverage is the actual reason to pick it over the cheaper option.
Holafly
Holafly only sells unlimited plans — there's no fixed-GB option at all. Pricing in October 2026 ran from $11.90 for 3 days up to $73.90 for 30 days, which works out to roughly $4/day short-term and about $2.46/day on the month-long plan. It runs on SoftBank and KDDI (au), and like every "unlimited" eSIM it applies a fair-use policy with a threshold the company doesn't publish — expect full speed for normal browsing, maps and messaging, with throttling possible if you stream video for hours on end.
Sakura Mobile
Sakura Mobile is the odd one out, and the only reason to pick it: it's the only provider here that sells a plan with a real Japanese phone number and voice calls attached, running on the Docomo network. Its travel eSIM (data-only, no number) starts around ¥1,250 (about $8.50) for short stays, but the plan most people actually want from Sakura is the voice+data SIM — from ¥2,980/month (about $20) for 5GB plus a ¥5,500 (about $37) activation fee. That's expensive next to the other three for a one-week holiday, and makes sense mainly if you need a callback number for a reservation, a delivery, or a longer stay of a month or more.
Price for a typical 7-day trip
Lining the four up for roughly the same use case — a one-week visit, moderate data use (maps, messaging, some photo uploads) — makes the gap clearer than any single provider's own pricing page will:
| Provider | ~7-day price | Data | Network | Phone number |
|---|---|---|---|---|
| Airalo | $8.00 (3GB) | Fixed, several tiers | SoftBank + au | No |
| Ubigi | ~$25 (8-day unlimited) | Unlimited or fixed | Docomo + au | No |
| Holafly | $27.50 (unlimited) | Unlimited only | SoftBank + au | No |
| Sakura Mobile | ~$46 (5GB + activation) | Fixed, monthly | Docomo | Yes |
Prices and plans change — always check the provider's own pricing page before you buy: Airalo Japan, Ubigi Japan plans, Holafly Japan, Sakura Mobile travel eSIM.
Which one for your trip
- City-only trip (Tokyo, Osaka, Kyoto, standard shinkansen routes): Airalo. Cheapest, and the SoftBank/au network is fine where most visitors spend their time.
- Trip includes somewhere rural — mountains, small islands, countryside driving: Ubigi, for the Docomo coverage. We've felt this gap ourselves diving around Okinawa's outer islands, where a SoftBank-only signal drops well before a Docomo one does.
- You want to stop thinking about data entirely and don't mind paying for it: Holafly, with the fair-use caveat in mind — it's for normal use, not hours of daily video streaming.
- You need an actual +81 number — for a hotel that calls to confirm, a delivery, a long stay: Sakura Mobile is the only one of the four that offers it, at a real price premium.
Whichever you pick, buy and install it before you fly rather than at the airport — our full guide to choosing and setting up a Japan eSIM covers the phone-compatibility and carrier-lock checks to run first, and this one covers exactly when the validity clock starts so you don't burn days before you've even landed.
FAQ
Which Japan eSIM is cheapest for a one-week trip?
Airalo, for data-only fixed plans — its 3GB/7-day tier runs about $8. If you want a Japanese phone number instead, Sakura Mobile is the one with that option, at a higher price.
Can I get a Japanese phone number with a travel eSIM?
Of the four we checked, only Sakura Mobile offers a plan with a real +81 number and voice calls. Airalo, Ubigi and Holafly are all data-only — fine for maps, messaging and apps, but you can't receive a call or an SMS verification code on them.
Will my eSIM work outside Tokyo and Osaka — on a small island or in the mountains?
It depends on the network behind the plan. Ubigi and Sakura Mobile run on NTT Docomo, which has the widest rural and mountain coverage of Japan's three carriers. Airalo and Holafly run on SoftBank and au, which are strong in cities but can thin out in genuinely remote spots.
Before you buy
Check your phone is actually eSIM-compatible and carrier-unlocked first — see our eSIM compatibility guide for the exact models and the unlock catch that trips people up. Then pick the provider that matches where you're actually going, not just the cheapest headline price, and install it a day or two before you fly.
