The only 30GB plan · Docomo and KDDI · a review history
Yesim in Japan
Yesim publishes two of the three good Japanese networks and sells a size nobody else does. It also had its Trustpilot score switched off during a fake-review cleanup, and we are going to keep saying so.
Every Yesim Japan plan
USD, checked 2026
| Plan | Price | Per GB | Notes |
|---|---|---|---|
| 1GB / 30 days | $4.44 | $4.44 | The longest window at 1GB. GigSky's is $2.99 for a week. |
| 5GB / 30 days | $10.56 | $2.11 | GigSky's 5GB over 30 days is $10.29. |
| 10GB / 30 days | $19.20 | $1.92 | The most expensive 10GB of the four we link. |
| 20GB / 30 days | $29.76 | $1.49 | Saily is $24.99 and Airalo $25.00 for the same size. |
| 30GB / 30 days | $39.60 | $1.32 | Nobody else sells exactly 30GB for Japan. |
| Unlimited day pass | from $4.20 a day | — | Yesim links a fair usage policy and never publishes the daily figure. You cannot know what you bought. |
The fixed plans above list KDDI as the network; Yesim's Japan page also carries separate plans on NTT Docomo. All plans are data-only with no SMS, and Yesim's Japan page states "ID verification: Not required". Prices in USD, checked 2026.
Yesim publishes KDDI and NTT Docomo
which is more than most
Of the four brands we can link, only two list NTT Docomo for Japan: GigSky, on every plan, and Yesim, on some. Docomo is the network with the deepest rural and mountain coverage in Japan, and outside the cities it is the whole decision. The network page explains why.
Read the plan before you buy: the fixed 1GB to 30GB plans list KDDI, and the Docomo plans are separate listings. KDDI is excellent on the Tokyo to Osaka corridor; if your route leaves it, pick a Docomo plan or a brand that lists Docomo on every plan. Ubigi lists KDDI, Docomo and SoftBank on one profile.
So why is Yesim not our default pick? Price and record. It is the most expensive 10GB of the four, its 20GB is nearly five dollars above Saily's, and it is the one brand here with a review history worth a paragraph of its own. If you want Docomo cheaply, GigSky is $16.79 for 10GB against Yesim's $19.20. Yesim earns its place at 30GB, where it has no exact competition.
The Trustpilot history, in full
because you should hear it from us
Where it stands now. As of 2026 the score is displayed again: 4.3 out of 5 across 2,996 reviews, with replies to 91 per cent of negative reviews. We checked the page twice on the day this was written, from two different tools, and found no suspension notice or consumer alert on it.
What we take from that. The enforcement worked and the profile came back clean, on the same review count it had during the suspension. That is a reasonable outcome and it is not the same thing as never having happened. A company whose reviews were once cleaned out from under it is a company that once had an incentive to game them.
What we do about it. Yesim stays on the site, its prices stay in every table, and this history is written next to it every time it appears. Yesim pays this site 18 per cent, the second highest rate of any brand we work with, which is precisely why we are not going to quietly stop mentioning the history. Compare that with Saily's 4.7 across 32,870 reviews, which has never had anything of the kind attached to it.
Yesim against the other three
size by size
| Yesim | GigSky | Airalo | Saily | |
|---|---|---|---|---|
| 1GB | $4.44 / 30d | $2.99 / 7d | $4.00 / 3d | $3.99 / 7d |
| 5GB / 30 days | $10.56 | $10.29 | $11.00 | $10.99 |
| 10GB / 30 days | $19.20 | $16.79 | $18.00 | $17.99 |
| 20GB / 30 days | $29.76 | none | $25.00 | $24.99 |
| 30GB | $39.60 | none | none | none |
| Unlimited, 30 days | not shown in USD | $65.99 | $69.00 | $71.99 |
| Unlimited cap published | no | 3.5GB/day, then slowed (speed not published) | 3GB/day, 1 Mbps | 5GB/day |
| Japanese networks | KDDI; Docomo on some plans | Docomo + SoftBank | KDDI + SoftBank | not published |
| Trustpilot | 4.3 · 2,996¹ | 4.3 · 8,403 | 4.2 · 48,959 | 4.7 · 32,870 |
¹ Score restored after a fake-review suspension. See the section above.
Yesim wins one row outright: the only 30GB. Its unlimited day pass starts at $4.20 a day, but Yesim will not say how much full-speed data a day it includes, and an unlimited plan with an unknown cap is not obviously cheaper than one with a printed cap. Saily's prices and 5GB cap in this table were checked on Saily's own Japan page in 2026.
Buying and activating Yesim
and one checkout quirk
- Buy on the Yesim website at home on wifi and check the currency selector. Reviewers have reported small unexpected charges at checkout when the display currency and the card currency differ, so confirm the total before you confirm the payment.
- Know what you are buying. If you take an unlimited plan, understand that the daily allowance is not published anywhere. If that bothers you, and it should, Airalo prints 3GB a day and 1 Mbps.
- Install the profile before you fly. It does not start counting until it connects in Japan.
- On landing: Yesim line on for data, home line on for calls with data roaming off. If it will not attach, set network selection to manual and pick NTT Docomo, then KDDI. Full setup and fixes.
Buy Yesim if, skip it if
the short version
Buy it if
- You want 30GB. Nobody else sells exactly that for Japan, and $39.60 is $1.32 a gigabyte.
- You want a 30-day window on a small plan: 1GB for $4.44 lasts a month.
- You have read the Trustpilot section and decided the history does not change your mind.
Skip it if
- You want 10GB or 20GB. GigSky and Saily are cheaper for both, by $2.41 and $4.77.
- You want unlimited with a cap you can plan around. Yesim publishes no daily figure at all.
- The review history bothers you. That is a reasonable position and Saily at 4.7 across 32,870 exists.
- You want a free trial before committing. Only GigSky offers one.
Yesim Japan questions
short answers
Is Yesim safe to use for Japan?
It sells real plans on real networks and people use it without incident. The history to know: Trustpilot suspended its score during a fake-review enforcement action and has since restored it, showing 4.3 across 2,996 reviews as of 2026. That is a recovered profile rather than an unblemished one, and we say so in every table it appears in.
Which network does Yesim use in Japan?
KDDI (au) on its fixed 1GB to 30GB plans, and NTT Docomo on separate Japan plans, per Yesim's own Japan page, checked 2026. GigSky lists Docomo on every Japan plan and is cheaper at 10GB.
Does Yesim have unlimited data for Japan?
Yes, as a day pass from $4.20 a day, checked 2026. It is the only unlimited plan among the brands we link where the daily allowance is not published anywhere. Yesim states a fair usage policy and gives no number, so you cannot know at what point it slows down.
What is the cheapest 30GB eSIM for Japan?
Yesim's, at $39.60 for 30 days, because it is the only brand selling exactly 30GB for Japan among those we track. The nearest alternatives are Ubigi's 25GB at $32 or 50GB at $55, and Nomad's 50GB at $35, none of which we can link. Checked 2026.
Is Yesim cheaper than Airalo for Japan?
At 5GB yes, $10.56 against $11.00 for the same thirty days. At 10GB no, $19.20 against $18.00. At 20GB no, $29.76 against $25.00. Yesim's genuine win in Japan is 30GB. Checked 2026.
The only 30GB plan sold for Japan
$39.60 over thirty days on KDDI. Yesim pays this site 18 per cent, the second highest rate of any brand we work with, and its Trustpilot score was once suspended during a fake-review cleanup. Both of those facts are on this page on purpose.
See Yesim Japan plansSources & freshness: Plan prices and networks from Yesim's own Japan page (yesim.app/country/japan), USD, checked 2026, before promo codes. Fair use: Yesim's linked unlimited-data policy, which gives no daily number. Trustpilot 4.3 across 2,996 reviews, checked 2026; the earlier suspension during a fake-review enforcement action is recorded in our own provider notes. Checkout currency reports come from third-party reviews. How we test.