Yesim eSIM for Japan (2026): Plans, Prices and What to Check First
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In a hurry? Yesim for Japan at a glance:
- Plans: unlimited data for any length from 1 to 30 days, or a fixed amount (1GB to 30GB) that lasts 30 days.
- Price: unlimited costs $4.20 a day for the first 7 days ($29.40 for a week), and the daily cost drops on longer trips. The 10GB plan is $19.20.
- Network: KDDI, the only operator Yesim lists for Japan. Hotspot is available.
- Check first: Yesim treats installing the eSIM as activation, and refunds only cover plans that haven’t been activated. Confirm your phone is compatible and unlocked before you install.
If you’re looking at a Yesim eSIM for Japan, the main things to know are how its plans are built and what the small print says. Yesim’s Japan plans are data only, and Yesim shows its Japan plan prices on its website, so you can see the cost of your exact trip length before you install an app. This guide goes through the plans, the network, how the unlimited plans are limited, and one refund rule that changes when you should install. The Yesim details here come from Yesim’s own Japan page and policies, checked in October 2026.
Yesim eSIM for Japan: the details in one table
| Plan types | Unlimited (1 to 30 days) and fixed data (1GB, 5GB, 10GB, 20GB or 30GB for 30 days) |
| Network in Japan | KDDI (one operator listed) |
| Plan type | Data only |
| Hotspot | Available |
| When the plan starts | When the eSIM connects to a compatible network |
| Use-by date | Activate within 90 days of purchase |
| Top-up | Not available on these plans |
| Speed limit on unlimited | Possible under the operator’s fair usage policy; Yesim doesn’t publish a number |
| Discount | 10% off when you buy 2 or more eSIMs |
Based on Yesim’s Japan eSIM page in October 2026. Plans and prices change, so check the current details before you buy.
Unlimited plans: what each trip length costs
Yesim lets you pick any number of days from 1 to 30. For the first week the price is a flat $4.20 a day. From day 8 each extra day adds less, so a 30-day plan works out at $2.20 a day. These are the prices we saw in US dollars when we checked from Japan; the amount shown in your country may differ.
| Trip length | Unlimited plan price | Per day |
|---|---|---|
| 3 days | $12.60 | $4.20 |
| 5 days | $21.00 | $4.20 |
| 7 days | $29.40 | $4.20 |
| 10 days | $34.57 | $3.46 |
| 14 days | $41.47 | $2.96 |
| 21 days | $52.32 | $2.49 |
| 30 days | $66.00 | $2.20 |
Fixed-data plans: 1GB to 30GB, valid for 30 days
The fixed plans all last 30 days, whatever your trip length. You pay for an amount of data and use it at your own pace.
| Data | Price | Per GB |
|---|---|---|
| 1GB | $4.44 | $4.44 |
| 5GB | $10.56 | $2.11 |
| 10GB | $19.20 | $1.92 |
| 20GB | $29.76 | $1.49 |
| 30GB | $39.60 | $1.32 |
Put the two tables side by side and the choice gets easier. For a 7-day trip, the 10GB plan costs $10.20 less than a week of unlimited, and the 20GB plan costs about the same as unlimited ($29.76 against $29.40). For two weeks, the 30GB plan at $39.60 is $1.87 cheaper than 14 days of unlimited. We’d pick 10GB for a week of maps, messages and photos, and move to unlimited only if you plan to share your connection or watch a lot of video. These plans have no top-up, so buy with a little room to spare.
What “unlimited” means on Yesim
Unlimited means you won’t be charged extra for the data you use. It doesn’t promise full speed all day. Yesim’s Japan page says data speed may be limited under the network operator’s fair usage policy, and its policy page says the operator might reduce your speed once you pass its high-speed allowance, until the daily or monthly cycle resets. Yesim says it adds no limits of its own and charges no overage fees.
Yesim doesn’t publish how much data you get before the slowdown, or how slow the connection becomes. By its own description, messaging and navigation should still work while video streaming and large downloads may suffer. If a known limit matters to you, a fixed-data plan gives you a set amount to plan around.
Install after you land, and why refunds make that matter
Yesim tells Japan customers to install the eSIM when they arrive: buy before the trip, then install and switch it on at your destination. The plan’s validity period begins when the eSIM connects to a compatible network, and you have 90 days from purchase to activate it.
The refund policy is the reason to follow that advice. You can ask for a refund within 30 days of purchase, but only if the plan hasn’t been activated, used or expired, and Yesim counts installing the eSIM profile as activation. So once you install, the refund window closes. Yesim asks you to make sure, before you buy, that your phone supports eSIM and isn’t locked to a carrier; at the latest, confirm both before you install. On an iPhone, open Settings > General > About; next to Carrier Lock it should say “No SIM Restrictions”.
If you install at the airport, you can use the free WiFi there. Our guide to getting an eSIM in Japan after you arrive lists the WiFi network names at Narita and Haneda.
Network, hotspot and your home number
Yesim lists one operator for Japan, KDDI, with 5G. Its page adds that speed depends on your device and location, so treat 5G as available where the network offers it. Coverage is listed for Tokyo, Osaka, Kyoto, Sapporo, Fukuoka and other cities.
Hotspot is available, so you can share data with other devices, like a travel partner’s phone. The eSIM is data only. Yesim says you can use it alongside your regular SIM and keep your number for WhatsApp, Telegram and similar apps. One QR code works on one phone only.
How Yesim differs from Airalo, Klook and Ubigi
We compare those three in detail elsewhere, so here are only the differences that affect a choice. Prices aren’t compared below, because we checked each company on different dates and in different currencies.
- Trip length: Yesim and Klook both let you pick any length from 1 to 30 days. Airalo’s unlimited plans come in set lengths of 3, 5, 7, 10, 15 or 30 days.
- Unlimited limits: Klook states its limit: 10 GB a day at full speed, then 128 kbps. Yesim gives no number.
- Network: Yesim lists KDDI. Ubigi lists KDDI, NTT Docomo and SoftBank. Airalo lists SoftBank, KDDI and Rakuten, and Klook lists SoftBank 5G or IIJ (Docomo) 4G LTE depending on the plan.
- Where you buy: Yesim shows its Japan plan prices on its website. Klook’s website shows a starting price, and you continue in its app to buy.
For the full picture, see our comparison of Airalo, Ubigi and Klook. Our Airalo vs Ubigi comparison does compare prices for those two: it lines up six plans that both companies sell, checked on the same day in US dollars.
Who Yesim suits
- Your trip is an odd length (8, 12 or 20 days): you pay for exactly the days you need.
- You’re staying three weeks or more: the daily cost of unlimited falls to $2.49 at 21 days and $2.20 at 30.
- You’re traveling as a pair or family: two or more eSIMs get 10% off, and hotspot is available if one phone needs to share.
- You want a stated speed limit before you buy: look at Klook, which publishes its 10 GB a day figure.
- You’d rather install at home and keep a refund option: Yesim’s rules work against that, so read another provider’s terms first.
See Yesim prices for your trip length →
Frequently asked questions
How much is a Yesim eSIM for Japan?
When we checked in October 2026, unlimited plans cost $4.20 for 1 day, $29.40 for 7 days, $41.47 for 14 days and $66.00 for 30 days. Fixed plans ran from $4.44 for 1GB to $39.60 for 30GB, each valid for 30 days.
Which network does Yesim use in Japan?
Yesim lists KDDI as its one network operator in Japan.
Does Yesim slow down unlimited data in Japan?
It can. Yesim says the network operator may reduce speed under its fair usage policy, and it doesn’t publish the amount of data that triggers this.
Can I get a refund from Yesim?
You can request one within 30 days of purchase if the plan hasn’t been activated, used or expired. Installing the eSIM profile counts as activation.
Can I use hotspot with Yesim in Japan?
Yes. Yesim’s Japan plans list hotspot as available.
Can I add more data if I run out?
Yesim’s Japan plans list balance top-up as not available, so choose a size with some margin.
Final thoughts
Yesim’s Japan eSIM is easy to price: pick your exact number of days for unlimited data, or a 30-day fixed plan from 1GB to 30GB, and the plan prices are on the website. The trade-offs are an unlimited plan with no published speed limit and a refund policy that ends when you install. Check that your phone is unlocked, decide between 10GB and unlimited for your trip, then install it once you land.
Still comparing? Our Airalo vs Klook comparison covers two other options, and our eSIM setup guide walks you through installing one.
