Reddit Japan eSIM Network Review Report
Reddit Japan eSIM Network Review Report
Data source: Reddit (r/JapanTravelTips, r/JapanTravel, r/eSIMs, etc.)
Sampling period: Discussion posts from 2025-07 to 2026-05
Sample size: 10 high-engagement posts + approximately 500 comments
I. Overall Review Overview
The Japan travel eSIM market is very mature, and the vast majority of user feedback indicates it is usable and basically stable. However, there are obvious differences between brands in terms of network routing, price, rural coverage, and app compatibility.
Core consensus:
- All eSIMs essentially rent networks from Japan's three major carriers (NTT Docomo / SoftBank / KDDI), with little difference in underlying coverage
- Differences mainly come from IP routing strategy (whether it's a local IP), price, customer service response, and throttling strategy
II. Detailed Brand Reputation Analysis
1. Ubigi (French company, IIJ/NTT Docomo network)
| Dimension | Rating |
|---|---|
| Coverage | ⭐⭐⭐⭐⭐ Uses Docomo network, widest rural coverage, including Japanese Alps, Mount Koya, etc. |
| Speed | ⭐⭐⭐⭐ Wide 5G coverage, but some users report "full signal but no internet" (Google Maps takes 2 minutes to load) |
| Price | ⭐⭐⭐⭐ Medium to high, Expo Osaka packages available throughout Japan |
| App Compatibility | ⭐⭐⭐⭐⭐ Does not block banks/social media |
| Customer Service | ⭐⭐⭐ Some users report unhelpful support, unable to resolve disconnection issues |
User review excerpts:
"Ubigi covers well in Tokyo, Kyoto, and rural areas, used it 2-3 times without issues." — Highly upvoted positive
"5G signal is full but internet completely doesn't work, all friends using Ubigi encountered the same problem." — Highly upvoted negative
"Ubigi sometimes has unstable connections, I won't use it again." — Medium rating
Key reminder: Negative reviews focus on specific devices (Pixel phones) or specific time periods, possibly device compatibility issues. Most users have no problems.
2. Airalo (Globally renowned, multi-network partnership)
| Dimension | Rating |
|---|---|
| Coverage | ⭐⭐⭐⭐ Excellent city coverage, but few disconnection reports in rural areas |
| Speed | ⭐⭐⭐⭐ Usually shows LTE (not 5G), sufficient for daily use |
| Price | ⭐⭐⭐⭐⭐ 20GB/30 days about $22-35 CAD, good value |
| App Compatibility | ⭐⭐⭐⭐ Few reports of TikTok and some apps being inaccessible (VPN can solve) |
| Customer Service | ⭐⭐⭐⭐ Has refund cases |
User review excerpts:
"Airalo connects well in Okinawa remote islands and Wakayama rural areas." — Highly upvoted
"Airalo suddenly disconnected after 10 days, bought another one and it also disconnected, very frustrating." — Negative
"Airalo died today, still have 3 days of trip, but customer service refunded the remaining value." — Medium
"Better signal than my home in Ireland — Tokyo, Kyoto, Hiroshima, Osaka 5G, Hakone 4G." — Highly upvoted
Key reminder: Negative reviews focus on disconnection mid-use or sudden speed drops, possibly due to data exhaustion or plan limits. Recommend confirming whether unlimited plans are truly unlimited before purchase.
3. Saily (Emerging brand)
| Dimension | Rating |
|---|---|
| Coverage | ⭐⭐⭐⭐ No problem in major cities, less feedback from rural areas |
| Speed | ⭐⭐⭐⭐ Speed sufficient for daily use |
| Price | ⭐⭐⭐⭐ Competitive pricing |
| App Compatibility | ⭐⭐⭐⭐ No blocking reports |
User review excerpts:
"Saily worked perfectly last June, good speed, only used 9GB in 11 days in Tokyo/Osaka/Nagoya." — Positive
"Saily connected to Hong Kong server, gave me Chinese IP address. JJesim uses IIJ/NTT network, lower latency." — Technical comparison
4. Holafly (Focuses on unlimited plans)
| Dimension | Rating |
|---|---|
| Coverage | ⭐⭐⭐⭐⭐ Excellent performance including rural areas like Kumano Kodo |
| Speed | ⭐⭐⭐⭐ Unlimited data but may be throttled |
| Price | ⭐⭐⭐ About €45 for 2 weeks (expensive) |
| App Compatibility | ⭐⭐⭐⭐⭐ No blocking |
User review excerpts:
"Used both Holafly and Ubigi, Holafly slightly better in rural areas." — Comparative review
5. JJesim / Journey Japan Esim (Chris Broad / Abroad in Japan brand)
| Dimension | Rating |
|---|---|
| Coverage | ⭐⭐⭐⭐⭐ Based on IIJ/NTT network, full coverage in Japanese Alps |
| Speed | ⭐⭐⭐⭐⭐ 20GB fast, hotspot sharing smooth |
| Price | ⭐⭐⭐ Slightly more expensive than mainstream brands by a few dollars |
| App Compatibility | ⭐⭐⭐⭐⭐ Real Japan IP, no geo-restriction issues |
User review excerpts:
"JJesim more stable than Ubigi, Ubigi 5G/LTE often disconnected before, IIJ's LTE is very stable." — Highly upvoted
"Can access internet 30 seconds after landing, hotspot sharing to other devices for streaming no problem." — Highly upvoted
"Full coverage in Japanese Alps, only no signal in tunnels." — Highly upvoted
Key advantage: Uses real Japan local IP (not roaming routing), so won't encounter issues where some Japanese services refuse access due to IP detection. This is what technical users value most.
6. Mobal (Japanese domestic brand)
| Dimension | Rating |
|---|---|
| Coverage | ⭐⭐⭐⭐⭐ Perfect coverage throughout Japan including rural areas |
| Speed | ⭐⭐⭐⭐ Provides voice+SMS+data, true Japanese SIM |
| Price | ⭐⭐ Expensive, but offers 50GB large data packages |
| Customer Service | ⭐⭐⭐⭐⭐ Japanese domestic support |
User review excerpts:
"Mobal 50GB enough for a month. Rural areas like Hakone, tour guide's signal was bad but we had full bars." — Highly upvoted
7. BillionConnect / MobiMatter (High cost-performance)
| Dimension | Rating |
|---|---|
| Coverage | ⭐⭐⭐⭐⭐ Based on IIJ/NTT network |
| Speed | ⭐⭐⭐⭐ Provides local Japan IP |
| Price | ⭐⭐⭐⭐⭐ 20GB/30 days only $12, king of value |
User review excerpts:
"Used BillionConnect last year, half the price of Ubigi, same good effect." — Highly upvoted
"MobiMatter (IIJ) much cheaper than Ubigi/Airalo, local IP, LTE speed sufficient." — Highly upvoted
8. Sakura Mobile (Japanese domestic)
| Dimension | Rating |
|---|---|
| Coverage | ⭐⭐⭐⭐⭐ Full coverage from Osaka to Sapporo |
| Speed | ⭐⭐⭐⭐⭐ High speed |
User review excerpts:
"Sakura Mobile 5 weeks of use, from Osaka to Sapporo, no problems at all." — Positive
III. Key Issues and Pitfall Avoidance Guide
1. International Roaming Fee Trap ⚠️
Multiple users (especially AT&T users) reported: Even when using eSIM, the main SIM card may still be charged international roaming fees.
Reasons:
- Main SIM's data roaming not turned off
- iPhone "Allow Cellular Data Switching" feature automatically switches back to main card when eSIM signal is weak
- Making/receiving calls or sending SMS triggers roaming
Solutions:
1. Turn off main SIM's data roaming before departure (Settings > Cellular > Main SIM > Data Roaming OFF)
2. Or completely disable the main SIM (Settings > Cellular > Main SIM > Turn OFF)
3. Turn off "Allow Cellular Data Switching" (iPhone settings)
4. Cancel carrier's International Day Plan (like AT&T)
2. IP Address / Routing Issues 🌐
Problem: Some plans from Airalo, Ubigi, etc. don't use Japan local IP, instead routing traffic to Hong Kong, Singapore, or US servers.
Impact:
- Some Japanese local services (like streaming, banking apps, government websites) will detect IP is not in Japan and refuse service
- Increased latency (200-500ms)
- Apps like Spotify will push foreign language ads
Solution: Choose eSIMs explicitly marked "Japan IP / Local IP / Non-roaming", such as:
- JJesim (IIJ network)
- BillionConnect / MobiMatter (IIJ network)
- Mobal (Japanese domestic SIM)
- Sakura Mobile (Japanese domestic)
- Trip.com eSIM (SoftBank 5G, marked Japan IP)
3. Unlimited Data ≠ Truly Unlimited 🚫
Problem: Many "unlimited" plans will severely throttle after exceeding a certain threshold.
Reddit user suggestions:
- For 2-3 week trips, 20GB is usually sufficient (maps, social media, messaging, searching)
- If watching videos/streaming, recommend buying truly unlimited plans (like KDDI partnership plans, no daily throttling)
- Confirm throttling threshold: some plans drop to 1Mbps after exceeding 2GB/day
4. Device Compatibility 📱
- eSIM requires phone support: iPhone XS and above, Pixel 3 and above, most recent Android flagships
- Carrier-locked phones cannot use eSIM (need to unlock first)
- Pixel phone users have reported compatibility issues with some eSIMs
IV. Recommended Selection Matrix
| Need Type | Recommended Brand | Reason |
|---|---|---|
| Pursuing stability + rural coverage | Ubigi / Mobal / JJesim | Docomo/IIJ network, widest rural coverage |
| Pursuing value | BillionConnect / MobiMatter / Airalo | 20GB/30 days $12-22 |
| Pursuing real Japan IP | JJesim / BillionConnect / Mobal | No roaming routing, no obstacles accessing Japanese local services |
| Need voice+SMS | Mobal / Physical SIM | Real Japanese phone number |
| Lazy person's choice | Airalo / Ubigi | Install directly from app, activate on landing |
| Long-term stay (>1 month) | Mobal / Sakura Mobile | Large data packages, domestic service |
| Short-term city trip (<2 weeks) | Airalo / Ubigi / Saily | Cheap, perfect city coverage |
V. Installation and Setup Recommendations
1. Purchase before departure: Most eSIMs delivered via email/app within 10 minutes
2. Activate before landing: Activate on the plane or just after landing, ensure network as soon as you disembark
3. Keep main number: eSIM is data-only, main SIM can still receive calls/SMS (but turn off data roaming)
4. Hotel WiFi assistance: Japanese hotel WiFi is generally good, can save eSIM data
*Report generated based on real user discussions on Reddit 2025-2026*