Japan
eSIM.Fast 5G data plans. Instant activation, no SIM swap.

A great Japan eSIM needs three things: coverage on Japan's dense networks, clear pricing, and instant setup. Flysimio connects to NTT Docomo, SoftBank, and au — the three carriers that blanket Japan with 4G/LTE and 5G, from central Tokyo and Osaka to the Shinkansen corridors and rural Hokkaido. Plans are prepaid with no contract and no roaming surprises, so the price you see is what you pay. Your QR code arrives by email within seconds of checkout and installs in under a minute, every plan includes mobile hotspot at no extra cost, and there's a 7-day money-back guarantee. It's the easy way to skip the airport SIM counter and land in Japan already connected. Adding more of Asia to the trip? Compare our Thailand eSIM plans or a single Asia regional eSIM.

Getting online in Japan takes about two minutes. First, confirm your phone supports eSIM — any iPhone from the XS (2018) and most Android flagships since 2020 qualify. Choose your Japan plan on Flysimio and pay with card, Apple Pay, or Google Pay; a QR code lands in your inbox seconds later. On home Wi-Fi before you fly, open Settings → Cellular → Add eSIM on iPhone (or Network & Internet → SIMs → Add eSIM on Android) and scan it — the manual code is included too. Keep your home line as default until you arrive. When you land at Narita, Haneda, or Kansai, your Flysimio line connects automatically to a Japanese network — no kiosk, no physical SIM, no queue.

Most visitors over-buy. For light use — Google Maps, translation apps, messaging, and email — around 300 MB a day is plenty, so a 3–5 GB plan covers a week comfortably. Add social media, photo sharing, and music and you'll want roughly 700 MB a day, making a 10 GB plan ideal for a two-week trip across Tokyo, Kyoto, and Osaka. If you stream on the Shinkansen, video-call, or tether a laptop, plan for 1.5 GB or more per day or choose an unlimited daily plan. Not sure? The data calculator above turns your travel style and trip length into a recommendation — and you can top up mid-trip if you run low.

Flysimio runs as a second line beside your usual SIM, so you keep your home number for calls and texts while your Japan data flows over the eSIM — standard dual-SIM behaviour on iPhone XS and later and most Android phones from 2018. After installing, set the Flysimio eSIM as your cellular-data line and switch on Data Roaming for that line only; it just lets the eSIM attach to Japanese networks, and there are no roaming fees. Leave your home SIM on for iMessage and calls, or turn it off to avoid your own carrier's charges. If you're not sure your model is supported, check the compatibility page before buying.

No. A Flysimio Japan eSIM is data-only, so there is no Japanese number attached: it cannot receive an SMS verification code and cannot take a call over the mobile network. Mobile hotspot is included at no extra cost and without throttling, so you can share the connection with a laptop, tablet, or travel companion and spend your full allowance freely — handy on long Shinkansen rides. For calls and messages, LINE is the default in Japan and WhatsApp, FaceTime, and Google Meet all work normally over data, while your home number stays reachable on your primary SIM because almost every recent phone is dual-SIM. If you specifically need a Japanese number — for a domestic booking system or a service that insists on SMS to a local line — that needs a Japanese carrier SIM with residency paperwork, not a travel data eSIM, and we would rather say so up front.

For a few days in Tokyo or a quick business trip, a small 1–5 GB plan on a 7-day validity is the most economical choice. For a two-week rail journey or a longer stay, a 10–20 GB plan or an unlimited daily option lets you navigate, translate, and stream without watching a meter. Because Flysimio gives you six months to activate, you can buy before you leave home and the validity only starts counting when your eSIM first connects in Japan. There's no contract and nothing to cancel — when the plan ends it simply stops, and you can top up or rebuy for your next trip.

A Japan eSIM here is prepaid in the strict sense: you pay once for a set amount of data and a set validity window, and that is the whole transaction. No contract, no credit check, no deposit, no monthly bill, and nothing that renews on its own — when the data or the validity runs out, the plan stops. That is the practical difference from a Japanese carrier line, which expects residency paperwork, and from an airport pocket-WiFi rental, which you have to queue for on arrival and physically return before you fly home. There is nothing to collect and nothing to give back: you buy before you leave, install over Wi-Fi at home, and the plan wakes up when your phone finds a Japanese network on landing. The plan selector above shows every size with its price per gigabyte, so you can see how the cost per gigabyte improves on the larger plans instead of guessing. New to this? How buying an eSIM works walks through the whole process.

Not genuinely unlimited, from us or from anyone else — and this is the most over-promised thing in the category. Our Japan daily plans give a full-speed allowance each day that resets every 24 hours and then slows for the rest of the day, and we label them by that daily allowance rather than calling them unlimited, because the allowance is the number that decides what you can actually do. Competitors mostly work the same way under a different word: Airalo bills a pass as "Unlimited" that is 3 GB per day at full speed and then throttled to roughly 1 Mbps, and Nomad's "Unlimited" is a daily high-speed allowance that resets every 24 hours and then drops to about 512 kbps. Holafly is the real exception, with no daily high-speed cap and a fair-use policy instead, and it is priced accordingly. So the honest comparison is not unlimited versus limited — it is how much full-speed data you get per day and what you pay for it. For most Japan trips, where the heavy use is maps, translation and photo uploads rather than constant streaming, a fixed 10–20 GB plan works out cheaper for the same real-world experience. Every competitor figure we quote is dated and source-linked in the eSIM price index.