How I Used Ubigi eSIM In Japan To Stay Online

This is a sponsored post with Ubigi. I only share brands I personally use and trust, and the experiences described are mine.

Landing in Japan with no mobile data used to be one of my biggest travel anxieties. As a female solo traveller, trying to decode train routes, read unfamiliar signs, and hunt down the best ramen spots without internet is incredibly stressful.

I’ve tried multiple eSIM providers on past trips and almost every time something went wrong. The service wouldn’t activate, I’d run out of data at the worst time, or I couldn’t top up without Wi-Fi. I’ve spent way too much time searching for a signal instead of enjoying my destination.

On my most recent trip to Japan, I used the Ubigi eSIM and everything just worked. It connected right away, kept me online the entire trip, and didn’t require any troubleshooting. 

Today I’ll share exactly how Ubigi performed in Japan, how I set it up, costs and what you can expect if you use it on your own trip.

Why I Chose Ubigi In Japan

‘Offline’ top-ups:

This was the biggest win for me and the main reason why I wanted to try Ubigi eSIM ASAP. You can top up even if you have no data remaining or WiFi access. 

The app stays connected just for this and lets you top-up as long as you’ve set up the eSIM in your phone and you have cellular signal. This is a big deal if you run out of data in the middle of nowhere, I’ve been there before and it’s not pretty!

Strong coverage in Japan

Ubigi is one of the best eSIMs for Japan! It runs primarily on NTT Docomo, the country’s biggest network and it covers even rural areas. This is perfect, considering I wanted to visit remote villages too and report back on my blog!

Plan activation at landing

I got my data before leaving Bali, and it only activated once I arrived at Haneda Airport. No more stress trying to set it up at the airport or worrying about wasting days of validity before travelling.

As a female solo traveller, although I’m 35 years old, I know my parents still wait for me to text them and let them know I landed! So that was another valid point for me as I would usually need to wait until I get to the airport, hope to get WIFI and text them. 

Sometimes I wouldn’t find any WIFI or have to run to my next flight and my mum would go in full panic mode!

Flexible plans

As someone who travels constantly, having an eSIM that covers different countries and different data capabilities is EVERYTHING! Let me explain. 

When travelling to Japan, I normally add other trips nearby, like for example, Korea. 

With Ubigi eSIMs, you can actually use one single eSIM and select data packages for multiple countries. It’s ideal for digital nomads or long-term travellers who want a reliable nomad eSIM that works across destinations.

That’s exactly what I wanted! And while this is also seldom the case with other eSIMs, with Ubigi it was a lot more straightforward.

👉 Compare Ubigi Japan plans here and use the code OBSERVER10 at checkout for 10% off your plan.

My Experience With Ubigi eSIM In Japan

I was honestly expecting something to go wrong because with other eSIMs it usually did. But the moment I landed in Japan, Ubigi connected without me having to touch a thing. 

No panic at the airport, no searching for Wi Fi, it just worked. Here is how it went for me in terms of the plan I chose, how I set it up, and what the connection was like while travelling around Japan:

Data plan chosen

My plan included 25GB for a month and I was able to do anything I wanted easily. I’m normally very conservative with the packages I use, meaning I would most of the time get a 5GB plan per month and try to use WIFI as much as I possibly can. 

But let me tell you for Japan is different. I don’t know about you but I need a lot more data! And this is why: 

Most locals don’t speak English, so Google Translate is my best friend. I use the picture translation feature and microphone feature for when the bus driver (especially in Kyoto) gets mad at me because I still didn’t understand how much change I need to get to the destination and I need time to count my coins! All this back and forth on the app takes quite a bit of data. Trust me you don’t want to run out of it in the middle of a conversation while the driver is trying to explain how many Yen you owe!

I also use Google Maps and WhatsApp heavily. I know you can download the map in advance and use it offline but sometimes I get confused. Considering I always travel alone, I don’t really want to get lost! I need the online version that actually tells me exactly where to go. 

WhatsApp is also working 24/7 for me with videos and pictures, for all the times I get lost anyway and ask my local friends to come rescue me or even hotel staff (I know it’s embarrassing).

My review eSIM installation

Setting up the eSIM has been super simple. I opened the QR code on my laptop while I was working and scanned the code using my phone’s camera. The eSIM’s name “Ubigi” came out straight away and once selected it started working immediately!

Connection and coverage

The coverage in Japan was excellent. Even on the Shinkansen between cities, my signal stayed steady enough to keep using Translate and Maps without issues.

One feature I ended up using more than expected was tethering. In a café in Kyoto the Wi Fi kept dropping, so I simply turned on Ubigi and connected my laptop through hotspot. The connection was strong enough to upload files and answer emails, which saved me a lot of frustration.

👉 Get your Ubigi eSIM for Japan here and enjoy instant connection as soon as you land. Use OBSERVER10 for 10% off.

How Much Is It? 

For short trips of just a few days, plans start from around US$3 to 4. A small 1 to 3 GB package is usually enough for basic use such as Google Maps, Translate, and quick searches.

If you are visiting Japan for one week, the 10 GB plan is the most practical choice. The 7 day option costs about US$14, or you can choose the 30 day version for around US$17 if you want more flexibility. This will comfortably cover daily use of Maps, Translate, WhatsApp, and social media.

If you are staying two weeks, the 25 GB for 30 days plan is the best fit at about US$32. In Japan you will rely on Translate and Maps every single day, and the extra data gives you peace of mind. It also leaves room for photos, videos, hotspotting your laptop, and even video calls with your parents or friends when you are in a beautiful spot and want to share the view in real time.

Ubigi also offers bigger plans, even some popular ones with unlimited data, and also yearly or monthly options if you plan to visit Japan more than once within the year.

👉 Check current Ubigi Japan data plans here

How To Install The eSIM

Step 1. Create your Ubigi account

You can either download the Ubigi app from the App Store or Google Play, or sign up directly on the Ubigi website from your laptop. Both options work. I like browsing and buying plans on desktop, then using the app later to manage my data once the eSIM is installed.

👉 Start here

Step 2. Select Japan as your destination

In the app or on the website, choose Japan so you can see the available plans. 

Even if you only select one country, the Ubigi eSIM itself remains valid in over 200 destinations. This does not mean that your Japan plan will work in Korea or Thailand. 

It simply means that once the Ubigi eSIM is installed on your phone, you can reuse the same eSIM profile for other trips. All you need to do is buy a new plan for the country you are travelling to next, without reinstalling or scanning a new QR code.

Step 3. Pay through the app or website

Ubigi accepts Apple Pay, Google Pay, and most cards. Once you have paid, your plan is linked to your account but it only activates when you land in Japan.

Step 4. Install the eSIM with the QR code

After purchase, Ubigi sends a confirmation email with a QR code. You can open it on your laptop and scan it with your phone, or install it directly through the app. Either way, the eSIM will appear under “Ubigi” in your phone settings.

Step 5. Switch your data line to Ubigi

On iPhone go to Settings then Mobile Data then choose Ubigi for mobile data and turn on Data Roaming.

If you have an Android instead, go to Settings then Network and Internet then SIMs then select Ubigi for mobile data and turn on Roaming.

Ubigi Vs. Airalo in Japan

Choosing between Ubigi and Airalo for Japan can be tricky because both are popular eSIM providers. To make it easier, here is a side by side comparison of how they work in Japan:

Feature	Ubigi	Airalo
Coverage	Uses NTT Docomo. Strong nationwide. Runs on NTT Docomo, the biggest network in Japan, with strong 5G even on trains.	Good in cities. Weaker in rural. Covers Japan, works fine in cities, but some travellers report weaker signal outside urban areas.
Top up	Top up in app without Wi Fi. Can top up instantly in the app even without Wi Fi or data remaining.	Needs Wi Fi or data to top up. Top up requires Wi Fi or data, which can be difficult if your plan already ran out.
Ease of use	Simple app. Easy balance. One eSIM for many countries. Simple app, balance easy to check, eSIM installs quickly. One eSIM for over 200 destinations.	App ok. Balance less clear. Often new eSIM per plan. App is straightforward but balance tracking can feel less intuitive. Need to get a new eSIM or QR code each time you want a new data plan.
Price examples	10 GB 30 days ~ US$17. 25 GB 30 days ~ US$32. 10 GB for 30 days about US$17 25 GB for 30 days about US$32	10 GB 30 days US$18. 20 GB 30 days US$25. 10 GB for 30 days US$18 20 GB for 30 days US$25

👉 See Ubigi Japan plans here! I found it easier to set up and manage, especially when travelling solo

FAQs About Ubigi eSIM in Japan

Would I Recommend Ubigi?

Absolutely yes! I tried Ubigi first in Japan and then again in Bali (read more here), and both times it worked perfectly. The difference with Ubigi is that it just works. 

You land, switch it on, and you are connected. If you run out of data, you can top up instantly in the app, even without WiFi.

I once had the opposite experience in Kuala Lumpur with a different operator. My connection cut out on the way to a sightseeing tour and I had no idea how to reach the meeting point. I was following Google Maps religiously until the data disappeared, and I ended up wandering around for almost an hour trying to find Wi Fi. 

By the time I finally connected, the tour had already started and the guide had to come and pick me up. It wasn’t ideal and it taught me to take eSIMs very seriously.

As female solo travellers, being connected is not just about convenience. It is about safety and peace of mind. We need to know that we can always open Maps, send our location to a friend, or call a ride without worrying about being offline. Ubigi gives us that security while keeping travel simple.

👉 Check Ubigi Japan plans here if you want something that works straight away without needing Wi Fi to top up!