Which Japan SIM is cheapest for a 7-day trip?

For a pure-data 7-day trip, Airalo's Moshi Moshi 5GB plan at around ¥1,650 is usually the cheapest option, as long as 5GB is enough for your usage. Sakura Mobile's 7-day 4G unlimited plan starts around ¥4,200 — much more expensive but truly unlimited (with a 3GB/day soft cap). Mobal's monthly plans aren't optimized for 7-day trips, but become competitive for stays of 16 days or more, especially when you need a phone number.

Do any of these come with a Japanese phone number?

Only Mobal. Both Airalo and Sakura Mobile sell data-only eSIMs and SIMs aimed at travelers, with no Japanese phone number included. Mobal's Voice+Data SIM and Voice+Data eSIM each come with a real 070/080/090 number you can use for restaurant reservations, ride-hailing apps, delivery confirmations, and any service that sends SMS verification codes. If you don't need a phone number, an eSIM-only plan is fine.

Which network does each provider run on?

Mobal runs on SoftBank. Airalo's Moshi Moshi line uses KDDI (au) and SoftBank. Sakura Mobile offers a Docomo plan and a 5G au plan, depending on which package you pick. In urban Japan, all three networks deliver effectively the same experience. Docomo (Sakura) tends to win in rural and mountain areas; SoftBank (Mobal, Airalo) is fine for 95% of standard tourist itineraries.

Today I Learned

Mobal vs Airalo vs Sakura 2026: One Feature Decides the Japan SIM

Mobal vs Airalo vs Sakura Mobile in 2026 — real prices, data caps, and the one feature that splits the field: only one gives you a Japanese phone number.

Published 2026-05-08 · 7 min read · By Daichi

◇ Three smartphones laid side by side on a wooden table, each showing a different Japanese mobile carrier signal in the status bar, with a Tokyo subway map blurred in the background

The decision tree, in one sentence

Most “best Japan SIM” articles bury the actual decision under a wall of plan tables. Here it is plainly: if you need a Japanese phone number, you want Mobal. If you only need data and your trip is short, you want Airalo. If you want truly unlimited high-speed data and you’ll be in rural Japan, you want Sakura Mobile. The rest of this article is just the evidence.

The three providers, side by side

Mobal — the only one that gives you a phone number

Mobal is a UK-headquartered carrier reselling on the SoftBank network, aimed at long-stay visitors and residents. Their differentiator is simple and surprisingly hard to find elsewhere: a real Japanese 070/080/090 phone number issued at sign-up. They sell both physical SIM (delivered by post or pickup) and eSIM (instant QR delivery).

Voice+Data SIM: ¥3,960 SIM cost + from ¥1,650/month, plans 1GB / 5GB / 10GB / 30GB. Real Japanese phone number.
Voice+Data eSIM: instant delivery, same Voice+Data plans. Real phone number.
Voice Lite SIM: ¥3,300 SIM cost + ¥990/month, 500MB included, ¥2,500 flat once you exceed 3GB. Real phone number, very cheap if you mainly want a number for reservations and ride apps.
Network: SoftBank, 4G/5G in cities.

Airalo Moshi Moshi — the cheap data eSIM

Airalo is a global eSIM marketplace; “Moshi Moshi” is their Japan-branded line. Pure data, no phone number, no SMS, no voice. Install a QR code, land, connect.

3 days: 1GB ¥700, 3GB ¥1,250
7 days: 3GB ¥1,350, 5GB ¥1,650, 10GB ¥2,800
15 days: 5GB ¥1,750, 10GB ¥2,900, 20GB ¥3,950
30 days: 5GB ¥1,800, 10GB ¥2,950, 20GB ¥4,100
Unlimited tier (separate plans): from ¥1,500-ish for 3 days up to ¥8,000-ish for 30 days, throttled to 1Mbps after 3GB/day.
Network: KDDI (au) + SoftBank.

Sakura Mobile — the unlimited-and-rural pick

Sakura Mobile is Tokyo-based, English-speaking customer support, mostly Docomo network. Their travel line skips the phone number entirely (the “Voice SIM” they advertise is for residents on long-term visas), but they offer the cleanest truly unlimited experience for travelers.

7-day 4G Unlimited: from ~¥4,200 (3GB/day soft cap, then throttled).
7-day 5G Unlimited (au network): from ~¥5,000.
10-day, 21-day, 31-day options scale linearly; longer trips get multi-SIM bundles.
Network: Docomo (4G plan) or au (5G plan).
Pickup: airport counters at Narita, Haneda, Kansai; or hotel delivery; or eSIM QR.

”Best for X” — the honest cross-table

Scenario	Pick	Why
3-7 day trip, Tokyo + Kyoto only, just maps and translation	Airalo Moshi Moshi 5GB	Cheapest by a wide margin, ~¥1,350-1,650, no phone number needed for sightseeing.
14-30 day trip, mix of cities and a few rural spots	Mobal Voice+Data eSIM or Airalo 30-day	Mobal if you’ll book restaurants / ride-hail; Airalo if you stay app-light.
Restaurants you reserve via Tabelog, OpenTable, or by phone	Mobal Voice+Data SIM	Tabelog confirms reservations by SMS the day before. No JP number = silent cancellation.
Long stay (1-3 months), business meetings, banking	Mobal Voice+Data SIM	Phone number persists; you can keep the SIM for return trips.
Rural hiking, Hokkaido north, Kyushu interior	Sakura Mobile 4G Unlimited	Docomo coverage is meaningfully better in mountains.
Heavy hotspot use for a remote-working trip	Sakura Mobile 5G Unlimited	Truly unlimited (with 3GB/day daytime cap), no overage.
Family of 4 sharing one connection	Sakura Mobile multi-SIM	Discounts on 46/62/93-day bundles include multiple SIMs.
You only realized at the airport you needed data	Airalo Moshi Moshi via app	Instant QR delivery, no kiosk queue. (Mobal eSIM is also instant.)

The phone-number gap, expanded

This is the part most comparisons skip, because a data-only eSIM is enough for Google Maps and translation apps. But Japan still runs a lot of services through a Japanese phone number:

Restaurant reservations on Tabelog and OpenTable: confirmation SMS goes out the day before. No JP number, the message bounces silently and the restaurant may release your seat.
Ride-hailing: GO and DiDi (the Japanese answer to Uber) require SMS verification at sign-up. No JP number = no app.
Convenience-store package pickup: many e-commerce sites send a Japanese-format SMS code for konbini pickup.
Mobile Suica / Mobile PASMO registration on Japanese app stores: occasionally requires a JP number for SMS auth.
Restaurant queue apps (EPARK, Toreta) at popular chains: often SMS-only.

If your trip skips all of the above and you just want maps, translation, and Wi-Fi calls home, a data-only eSIM is enough. If you’ll do any of it, you save real time and real anxiety with a phone-number SIM.

We have a longer write-up on this trade-off in Japan, apparently, you actually do want a phone number — read it if you’re still on the fence.

Customer support in English

All three are English-friendly. Quick honest ranking based on documentation quality and response time in our experience:

Sakura Mobile — Tokyo office, real humans on chat and phone, opens early. Best for “my SIM isn’t activating and I’m at the airport now.”
Mobal — UK-based + Tokyo desk, email and chat. Slower than Sakura’s airport coverage but excellent for billing and account-level questions across a long stay.
Airalo — global app-based support, in-app chat. Fine for the 95% case; they’re a marketplace, so deep network issues bounce you to provider-side help.

My pick — and the honest disclaimer

For most readers of this site — short-to-medium trip, want to actually book the good restaurants, occasionally use a ride app — the boring practical answer is the Mobal Voice+Data eSIM for 16-31 day trips, or the Mobal Voice+Data physical SIM if you want the SIM mailed to your home before the flight. The phone number is the feature you don’t realize you needed until you don’t have it.

If you’re a stay-on-the-tourist-trail traveler with a 5-day Tokyo + Kyoto loop and no reservations to keep, save the money: get an Airalo 7-day 5GB plan and skip the rest of this comparison.

If you’re heading to rural Japan and want the unlimited safety net, Sakura Mobile’s 4G Unlimited plan is genuinely the best in that category.

The links to Mobal and Sakura Mobile in this article are affiliate links. The recommendations are the same ones I give friends.

Closing

Japan’s mobile market for tourists looks crowded, but it sorts cleanly into three roles: the data-only marketplace (Airalo), the unlimited-data specialist (Sakura), and the phone-number specialist (Mobal). Apparently the only honest way to recommend one is to ask which of those three things you actually need.