Guide
Disclosure: ESIM KIMONO is our store. Competitor facts come from their own pages and public reviews, checked 13 October 2026, each linked.
Short answer: there is no single winner; compare network, speed rule, hotspot and what happens when it fails. Ubigi is the only data eSIM here with Docomo, Sakura Mobile claims no speed restrictions, Mobal gives you a Japanese number, and ESIM KIMONO gives you KDDI at a flat 10 Mbps with no daily data cap and a human who answers.
You land at Narita after dark and the eSIM won't activate; the only fix in sight is a SIM counter queue, passport out. Two days later the family splits up at Shinjuku and your map stops loading. On day five a restaurant wants a QR payment and your data is crawling.
Headline prices don't tell you how a plan behaves in those moments. The network, speed rule, hotspot and support do.
| Provider | Network | Speed rule on unlimited | Hotspot | Worth knowing |
|---|---|---|---|---|
| Airalo | SoftBank + 1 other (Japan page) | 3GB per 24h at full speed, then 1 Mbps (FUP) | Allowed; counts toward the 3GB (review) | Change-of-mind refunds before activation only, some as app credit |
| Holafly | KDDI / SoftBank (Holafly) | Fair usage may slow speed for up to one day; threshold not published | 1GB per day | Plans up to 90 days |
| Ubigi | NTT Docomo and KDDI (Ubigi) | 25GB at full speed per 7-day plan, then 2 Mbps | Data sharing allowed (our 26 Sep check) | The only Docomo data eSIM here |
| Saily | KDDI and SoftBank (saily.com) | 5GB per day at full speed, then up to 1 Mbps | "Limitless hotspot sharing" | Highest daily allowance here |
| Nomad | KDDI au / SoftBank (getnomad.app) | Daily high-speed allowance, then 512 kbps (Nomad) | Not stated in the page text | Long-validity fixed plans |
| Sakura Mobile | au 5G | "Truly unlimited, with no speed restrictions" (Sakura support) | Capped at 6GB total on 7 days, 13GB on 14, 30GB on 30 | No speed cap claimed |
| Mobal | Docomo (mobal.com) | Not compared | Not compared | Real Japanese phone number; ID check; access code posted or collected in Japan |
| ESIM KIMONO | KDDI 4G/5G | Flat 10 Mbps from the first minute, no daily data cap (/fup/) | Most plans; each plan's rule printed at checkout | QR by email in minutes, no app, no account |
Our fixed plans run at full network speed, then 384 kbps once the data is used.
Whatever you buy, install on home Wi-Fi, turn Data Roaming on when you land, and keep our rescue card handy. It works for any brand.
Trustpilot, read 13 October 2026: Holafly: 4.7 from 114,820 reviews, 7.4% of them 1-2 star (Trustpilot). Airalo: 4.1 from 47,122 reviews, 20.1% of them 1-2 star (Trustpilot). Both cover every country. ESIM KIMONO has no Trustpilot profile yet.
In recent 1-2 star reviews that mention Japan:
On Reddit, Ubigi gets "set and forget" praise (r/JapanTravelTips).
The pattern: the eSIM won't connect or drops, or "unlimited" gets slow once a limit kicks in. Read the speed rule before you buy.
A first week in Tokyo and Kyoto. A fixed plan with a readable "after the data" rule. Ours slows rather than stops. Tokyo · Kyoto
A family on the JR Pass. One eSIM per adult, so nobody is stranded when the group splits. Check hotspot rules before teens share. Families
A heavy user or creator. A flat cap avoids the evening slowdown; that is what ours is built for. For no speed cap at all, Sakura Mobile.
Niseko, Hakuba or rural Hokkaido. Networks differ most in mountains. Ubigi offers Docomo plus KDDI; we are KDDI only. Ski guide
All-day hotspot: Saily. A Japanese number: Mobal. More than a month: Holafly, up to 90 days.
ESIM KIMONO is run by Fizen LLC. Fizen.io has 500,000+ app users and a strategic investment from Tether. Japan quality standards: KDDI licensed network, GSMA standard eSIM profile, card payments on Stripe (PCI DSS Level 1). We fit a Japan-only trip where you want a named network and a one-sentence speed rule, not one that needs Docomo, a phone number or more than a month.
It depends on the trip. Rural coverage: Ubigi (Docomo and KDDI). Steady heavy use: ESIM KIMONO, flat 10 Mbps on KDDI. No speed cap: Sakura Mobile. Japanese number: Mobal. Over a month: Holafly.
In cities, all three major networks perform well; differences show up in mountains and long tunnels. Among data eSIMs here, only Ubigi offers Docomo.
For most visitors a fixed plan is enough. Unlimited suits heavy video, calls and hotspot use, once you understand its speed rule.
We don't compete on price. Plans are priced for a carrier-grade network and a human who answers. Today's price is on the button below.
Mobal sells Voice+Data plans with a Japanese number. Ours is data only.
Competitor facts on this page were checked on 13 October 2026 on their own pages. The button above shows today's price.
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