Japan eSIM & SIM Prices Compared for Fan Trips: Exact Cost per GB (and When You Need a Real Phone Number)

Last checked: 9 November 2026 · Prices from official vendor pages

Written only from the vendors' official pages, checked on 9 November 2026. Prices are shown in the currency each vendor lists (Japanese yen or US dollars). Plans and prices change — confirm on the official page before you buy. This article contains no affiliate links.

A fan trip to Japan uses data differently from a sightseeing trip. You are refreshing a fan-club lottery result page, running a merch pre-sale app outside a venue, checking last-train times after an encore, and uploading photos from the arena floor. So the question is not just "what is the cheapest eSIM for Japan?" — it is "what does each option actually cost per gigabyte, and will it do the one job a data eSIM cannot do: receive an SMS code sent to a Japanese phone number?"

This guide answers both questions using only what each vendor states on its own official pages. Every price below was read on the vendor's official page on 2026-11-09.

A note on currencies: prices are shown in the currency each vendor charges (Japanese yen or US dollars) and are not converted in the tables, because the listed currency is what you actually pay. As a rough orientation only, ¥1,000 was about US$6.30 in November 2026.

The short version

• Lowest total cost for a normal fan trip: Sakura Mobile's 3GB/day eSIM (docomo) — ¥3,850 for 5 days, ¥5,610 for 10 days. Its per-GB rate is mid-table, but the cash outlay is the smallest of the fully priced options.
• Cleanest per-GB rate in US dollars: Ubigi's fixed pool — 10GB for 30 days at $16.50, which is $1.65/GB, and the unused data does not expire mid-trip.
• Cheapest per-GB on paper: NINJA WiFi's 10GB/day pocket WiFi at ¥132 per effective GB — but only if you actually use 10GB every day, and a pocket WiFi is a shared router, not a personal eSIM.
• The catch with every daily-cap plan: the allowance resets each day and unused data does not roll over. Per-GB figures for daily caps are a best case, not a typical case (see the honesty section below).
• No travel data eSIM gives you a Japanese phone number. If a step in your trip sends an SMS code to a Japanese number, a data-only eSIM cannot complete it. The official visitor routes to a real 070/080/090 number are Sakura Mobile's Voice + Data travel eSIM and Mobal's voice products (details and caveats in the phone-number section).

Cost per GB: the ~5-day trip

"Effective GB" means the high-speed allowance actually available over the trip. For daily-cap plans, that is the daily cap multiplied by the number of days — and it assumes you use the full cap every day. Yen and dollar prices are ranked within their own currency; they are not converted.

How the math works, using two examples: NINJA WiFi's 10GB/day plan costs ¥1,320 per day, so ¥1,320 × 5 days = ¥6,600, and 10GB × 5 days = 50GB, giving ¥6,600 ÷ 50 = ¥132/GB. Sakura Mobile's 3GB/day eSIM costs ¥3,850 for 5 days, and 3GB × 5 days = 15GB, giving ¥3,850 ÷ 15 ≈ ¥257/GB.

Cost per GB: the ~10-day trip

Sakura Mobile's eSIM improves on a longer trip: ¥5,610 ÷ 30GB = ¥187/GB at 10 days, and it stays the lowest total outlay of the fully priced eSIM options. Ubigi's pool holds the same $1.65/GB at any trip length within its 30-day validity, because the price does not depend on your trip length at all.

The honesty section: daily caps vs. a fixed pool

The per-GB winner in both tables is a daily-cap plan, and that result needs an asterisk. A 10GB/day cap only produces ¥132/GB if you genuinely use close to 10GB every single day. Use 3GB on a travel day and 1GB on a concert day, and the data you did not use is gone — it does not roll over to the next day. Your real cost per GB used is higher than the table figure, possibly much higher.

A fixed pool works the other way. Ubigi's 10GB is yours for the full 30 days: heavy use on concert day, light use on a travel day, no waste either way. That is why the pool's $1.65/GB is the most honest headline rate in this comparison even where it is not the lowest number in its column.

Two more comparability notes. A pocket WiFi is a separate device that several people and devices can share, so its per-GB cost is not like-for-like with a personal eSIM — it is included because fan groups travelling together genuinely use them, and because it is the priced pocket-WiFi option whose full rate card is published. And Airalo, whose Japan eSIM ("Moshi Moshi," on SoftBank) is widely sold, is not in the computed tables: its official page lists plans from $4.00, but the full plan-by-plan price table could not be read in full for this guide, so rather than copy figures from other sites, Airalo is excluded from the math. Check its official page for current plan prices.

If you want unlimited data instead

Unlimited plans cannot be ranked per GB, so compare them on per-day cost and on what each vendor actually says about speed reductions:

• Sakura Mobile Unlimited eSIM (au/KDDI network): ¥4,565 for 5 days, ¥7,370 for 10 days. Sakura Mobile states there is no fair-use policy and no daily throttling on phone data. Hotspot use has a separate per-trip allowance (for example, 6GB on a 7-day plan and 15GB on a 15-day plan).
• Holafly Japan eSIM (unlimited): $20.50 for 5 days ($4.10/day), $36.50 for 10 days ($3.65/day). Hotspot sharing is capped at 1GB per day. Holafly's official product page does not publish a numeric fair-use or throttling threshold, so this guide does not state one — if the threshold matters to you, ask Holafly before buying, because it is not on the page.

Both are data-only. Neither gives you a phone number.

When you need a real Japanese phone number

Start with the baseline fact, stated in each vendor's own terms: the travel data eSIMs in this guide — Sakura Mobile's, Ubigi's, and Holafly's — are data-only. No Japanese phone number, no voice calls, and no carrier SMS. A data eSIM therefore cannot receive an SMS verification code that a Japanese service sends to a Japanese number. No amount of data fixes that; it is a different product.

Two official routes give a visitor a real Japanese number (070, 080, or 090 prefix):

• Sakura Mobile's Voice + Data travel eSIM combines the same 3GB/day data with a real Japanese phone number, calls, and SMS. The condition is identity verification in person: you must show your passport at an airport counter or Sakura Mobile's Shinjuku office (Narita and Haneda require an advance application). Sakura Mobile does not publish this product's price on the pages used for this guide, so confirm the price with them directly.
• Mobal's voice SIM/eSIM products assign a standard Japanese number on the docomo network, with incoming calls and incoming SMS free. On the official pages read for this guide, the voice eSIM itself was listed at ¥3,960 and the Voice-Only plan at ¥1,430/month. Two things to know before relying on those figures: other Mobal pages and campaigns show different prices for the same items (see the editor's notes), so treat the Mobal website's current checkout price as the real one; and a Japanese ID check is legally required for voice products, with the voice eSIM delivered as a physical access code by post or pickup, not by email. Buyers must be 18 or over.

Mobal also sells an add-on for receiving SMS while roaming, which it markets for concert tickets, app verifications, and online purchases in Japan. Use Mobal's own framing, not ours: Mobal states that many Japanese services, including event ticketing sites, send codes only to Japanese numbers — and Mobal does not guarantee that any given ticket site will accept its number. Whether a specific platform accepts a specific number is decided by that platform, per event.

That leads to the honest limit of this section. Which fan-trip steps require a Japanese number is decided platform by platform: ticket platforms' phone-verification steps, individual fan-club membership and lottery rules, merch apps, and reservation systems each set their own requirements, and those requirements were not verified platform by platform for this guide. What is verified is the product side of the equation: if a step in your fan trip sends an SMS code to a Japanese number, a data-only eSIM cannot complete it, and the two routes above are the official visitor options for a real number. Check your specific fan club's and ticket platform's rules — in Japanese, if necessary — before you rely on either route for a specific lottery.

So which one should you buy? 5 points to decide

1. Decide by total outlay first, per-GB second. For a typical 5–10 day fan trip, Sakura Mobile's 3GB/day eSIM has the lowest total cost of the fully priced eSIMs (¥3,850 / ¥5,610), and 3GB/day covers maps, social media, merch apps, and photo uploads for most fans. Per-GB rankings flatter plans you will not fully use.
2. If your usage swings wildly by day, buy a pool, not a cap. Concert days are heavy; travel days are light. Ubigi's 10GB / 30 days at $16.50 ($1.65/GB) wastes nothing across that pattern, and its 30-day validity covers trips of any length up to a month.
3. Treat pocket WiFi as a group product. NINJA WiFi's headline ¥132/GB (10GB/day plan, ¥1,320/day) is real math but assumes full daily use of a shared router. It makes sense for a group splitting one device, or one fan running several devices — not as a like-for-like replacement for a personal eSIM.
4. For unlimited, compare the throttling terms, not the word "unlimited." Sakura Mobile states no fair-use throttling on phone data for its unlimited eSIM (¥4,565 / 5 days, ¥7,370 / 10 days). Holafly ($20.50 / $36.50) caps hotspot sharing at 1GB/day and publishes no numeric throttling threshold on its product page. Those stated terms are the comparison — the label is the same, the products are not.
5. Solve the phone-number problem separately, and early. If your trip involves a fan-club lottery, a ticket platform with phone verification, or any step that texts a code to a Japanese number, a data eSIM will not do it. The official routes are Sakura Mobile's Voice + Data eSIM (in-person passport check; price not published on the pages read) and Mobal's voice products (ID check; posted access code; prices vary by page and campaign). Neither guarantees that a given platform will accept the number — verify your platform's rules before you build your application plan around one.

Whichever you choose, re-check the price and terms on the vendor's official page before you buy. Every figure in this guide reflects official pages as read on 2026-11-09, and travel eSIM pricing changes frequently.

Related guide: the phone-number question above matters most at fan-club lotteries — see Can Overseas Fans Enter ATEEZ Japan Fan-Club Lotteries? for how the residence rule, presale rounds and ID checks actually work.