Find the right prepaid Japan eSIM in under a minute. Our AI advisor matches you with the best 5G Unlimited or Fixed Data plan based on your trip length and data needs — all on the KDDI and NTT DOCOMO networks, with instant QR delivery and the Plan B Guarantee on every 5G plan. Start the chat above, or read the most common questions travelers ask below.
- How do I choose the right Japan eSIM plan?
- Match the plan to your trip length and how much data you use. Most travelers pick a 5G Unlimited plan on KDDI so they never count data, then choose the duration that covers their trip. If you are unsure, tell our AI advisor how many days you are travelling and it recommends the exact plan in seconds.
- Which network does a Japan Wireless eSIM use?
- All 5G plans — both Unlimited and Fixed Data — run on the KDDI network. 4G LTE plans run on NTT DOCOMO. Both carriers offer nationwide high-speed coverage across Japan, including airports, major cities, and transit hubs.
- Is the 5G Unlimited plan really unlimited?
- Yes. The 5G Unlimited plan on KDDI is designed for normal-to-heavy travel use under a Fair Usage Policy — there is no daily 3GB cap and no midnight data reset. Only extremely heavy or abusive usage may be subject to temporary speed management.
- What is the difference between Unlimited and Fixed Data plans?
- A 5G Unlimited plan (KDDI) gives you full-speed data with no daily counting. A Fixed Data plan gives you a set total amount of high-speed data for the whole validity period. The 4G Unlimited plan (NTT DOCOMO) offers up to 3GB per day at high speed, after which speed reduces to 256 kbps until the allowance refreshes at midnight Japan time.
- What is the Plan B Guarantee?
- Every KDDI 5G plan — Unlimited and Fixed — includes our Plan B Guarantee. If your eSIM cannot connect after you arrive in Japan, our Japan-based support team runs guided checks first. If your compatible device still cannot connect, we ship a free Pocket WiFi device to your hotel or accommodation at no extra charge so you stay connected for your trip.
- How fast do I receive my eSIM after buying?
- Delivery is instant. Your eSIM QR code is emailed to you immediately after purchase. You can install it at home over Wi-Fi before you fly, and it activates automatically when you arrive in Japan and turn on data roaming.
- Can I use hotspot or tethering with a Japan eSIM?
- Yes. Hotspot and tethering are supported. Each 5G Unlimited plan includes a high-speed hotspot data allowance; after it is used, sharing remains available at reduced speed to maintain network stability. On 4G Unlimited, up to 3GB per day is shared across devices.
- Can I get a refund if the eSIM does not work?
- It depends on the plan. KDDI 5G plans are covered by the Plan B Guarantee rather than insurance — guided support, then a free Pocket WiFi if your compatible device still cannot connect. On 4G plans you can add optional insurance at checkout; if purchased, you can request a refund (all charges except the insurance fee) within 30 days and before activation, for any reason. Always check device compatibility before buying.