Can I use an eSIM for studying in Japan? Comparing communication options for long-term stays.

When studying abroad in Japan, you will use your smartphone in various situations such as contacting schools, maps, transfer guides, translations, social media, and job hunting.

Therefore, it is important to prepare a means of communication that can be used immediately after arriving in Japan.

You can use eSIM while studying in Japan. It is especially convenient for those who want to use the internet immediately after arriving at the airport or are looking for a means of communication until their contract with a Japanese mobile phone company is completed.

On the other hand, for long-term studies of six months or more, it is necessary to compare not only data-only eSIMs but also SIMs with Japanese phone numbers and monthly contracts.

This is because you may be required to provide a Japanese phone number or SMS verification for schools, banks, part-time jobs, delivery services, and administrative procedures.

In this article, we will explain the benefits of using eSIM for studying in Japan, the necessary data capacity for long-term stays, the necessity of a phone number, and the differences between prepaid SIMs, monthly SIMs, and rental Wi-Fi.

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Can you use eSIM while studying in Japan?

If you have an eSIM-compatible smartphone, you can use a Japanese eSIM during your studies in Japan.

eSIM is a digital SIM that adds a communication plan to your smartphone without the need to swap physical SIM cards; it can be set up using QR codes and other methods.

You can purchase it online before arriving in Japan and set it up before or after your arrival, making it convenient as a means of communication right at the start of your study abroad.

By using a Japanese eSIM, you can access services such as:

• Google Maps
• Train and bus transfer guides
• Translation apps
• LINE and WhatsApp
• Checking emails from school
• Online classes
• Social media
• Web searches
• Video calls

You can check the currently available plans for Japan at Japan eSIM products and pricing plans.

Convenient situations for using eSIM while studying in Japan

Immediately after arriving in Japan

Upon arriving in Japan, you will need to move from the airport to your school, dormitory, or homestay.

If you prepare a Japanese eSIM before departure, you can use maps, transfer guides, and messaging immediately after arrival.

Until your Japanese mobile phone contract is completed

When contracting a Japanese monthly SIM, you may need identification documents, a residence card, an address, and a payment method.

Immediately after arriving in Japan, you may not have completed the address registration or bank account setup, making it impossible to contract right away.

During that time, you can use a short-term or approximately 30-day Japanese eSIM as a means of communication.

Short-term study or language training

For short-term studies lasting a few weeks to three months, you may be able to manage with just a travel or short-stay eSIM without a monthly contract.

Domestic travel during your study

Even if you primarily use Wi-Fi at school or in your dormitory, mobile communication is necessary when traveling within Japan.

You can also purchase additional Japanese eSIMs for the required duration.

Recommended communication methods differ between short-term and long-term studies

The recommended communication method varies depending on the duration of your study abroad.

For short-term studies, an eSIM that is easy to set up and does not require return is convenient.

For long-term studies, since there is a high possibility that a Japanese phone number will be needed, it is advisable to compare monthly SIMs and plans with phone numbers as well.

Comparing communication methods available for studying in Japan

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How to choose an eSIM for studying in Japan

Select a validity period that matches your study duration

eSIMs have usage periods set for 3 days, 7 days, 15 days, 30 days, etc.

If you choose a plan shorter than your study duration, you will need to add additional charges or purchase a new eSIM.

For studies lasting 1 to 3 months, check the following points:

• Can you repeatedly purchase a 30-day plan?
• Can you add charges to the same eSIM?
• Can you extend the usage period?
• Is a new QR code setup required?
• Total cost if used for a long time

Select the necessary data capacity

During your studies, you will likely use your smartphone more than during travel.

The necessary capacity will vary depending on whether there is Wi-Fi at school or in the dormitory and whether you will take online classes.

Actual data usage will vary based on video quality, online class duration, tethering, and cloud synchronization.

For estimates by app, please check data usage estimates.

Check if additional data and extensions are supported

In long-term studies, there is a possibility of running out of data capacity earlier than planned.

Before purchasing, check the methods for adding charges, extending the period, and repurchasing.

Even if additional charges are not supported, you can purchase a new Japanese eSIM and switch the data line.

Check if tethering is supported

If the Wi-Fi at school or in the dormitory is unstable, you may use your smartphone's tethering to connect your computer.

Some products may have restrictions on tethering, so check the following items:

• Is tethering supported?
• Is there a limit on tethering capacity?
• How many devices can be connected simultaneously?
• Can it be used even after speed restrictions?
• Is APN setup required?

Check the conditions for speed restrictions

Even with unlimited plans, there may be daily high-speed data limits or fair usage policies in place.

If you will be using online classes or videos, check the high-speed communication limits and the speed after restrictions.

Check the support system

Immediately after starting your studies, it may be difficult to set up or inquire in Japanese.

It is reassuring to check the supported languages, inquiry methods, and support hours before purchasing.

For setup and communication troubles, please refer to Japan eSIM support.

Is a phone number attached to the eSIM necessary for studying in Japan?

If you are only communicating with family and friends via LINE or WhatsApp during a short language training or exchange program, a data-only eSIM will suffice.

On the other hand, for long-term studies, there may be situations where a Japanese phone number is necessary.

Situations where a Japanese phone number may be required

• Registering contact information with schools or universities
• Opening a bank account
• Applying for part-time jobs
• Contacting real estate or student dormitories
• Receiving deliveries
• Calling hospitals or government agencies
• SMS verification for Japanese services
• Registering for credit cards or payment services

Data-only eSIMs typically do not come with a Japanese phone number or SMS functionality.

If you need a Japanese phone number, please consider eSIM with a phone number or a Japanese monthly SIM.

If you only use LINE or WhatsApp, is a plan with a phone number unnecessary?

If you have already registered your LINE or WhatsApp account, you can use the data communication of the Japanese eSIM for messaging and calls.

However, if you reinstall the app, log out, or change devices, you may need SMS verification to the registered phone number.

Make sure to maintain your main line overseas or check your login information before departure.

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Can you use your overseas main line and Japanese eSIM simultaneously?

If you have a dual SIM-compatible smartphone, you may be able to use your main line from overseas and the Japanese eSIM simultaneously.

The recommended settings are as follows:

By keeping your overseas main line, you may be able to receive authentication SMS for banks and SNS.

However, making and receiving calls or sending SMS through the main line may incur international roaming charges.

If you are concerned about costs or do not need the main line, turn it OFF.

Recommended communication methods by study duration

Short-term study of 1 week to 1 month

For short-term studies, the Japanese eSIM that does not require delivery or contract procedures is convenient.

If there is Wi-Fi at your school or accommodation, plans of around 3 to 10GB will be easy to use.

Language study of 1 to 3 months

eSIMs that can renew the 30-day plan or large capacity plans are candidates.

If you do not expect to need a Japanese phone number, a data-only eSIM may suffice.

Exchange study of 3 to 6 months

Considering the total communication costs, a Japanese monthly SIM may be cheaper than repeatedly purchasing short-term eSIMs.

Compare phone numbers, SMS, contract periods, and cancellation fees.

Long-term study of 6 months to 1 year or more

For long-term studies, a monthly SIM with a Japanese phone number may be easier to use.

You can use an eSIM immediately after arriving in Japan and switch to a monthly SIM once your address registration and bank account setup are complete.

How to use both Japanese eSIM and monthly SIM

For long-term studies, you can gradually switch communication methods as follows:

1. Purchase a short-term Japanese eSIM before departure
2. Start communication with the eSIM immediately after arriving in Japan
3. Complete address registration and residence card procedures
4. Prepare a bank account and payment method as needed
5. Contract a Japanese monthly SIM or a plan with a phone number
6. Confirm the connection of the new line
7. Turn OFF the short-term eSIM

This method allows you to avoid any period without communication immediately after arriving in Japan and transition to a long-term plan.

Things to check before studying in Japan

• Is your smartphone compatible with eSIM?
• Is the device's SIM lock removed?
• Does it support the frequencies used in Japan?
• Is it compatible with dual SIM?
• Is the validity period suitable for your study duration?
• Is there sufficient data capacity?
• Is a Japanese phone number necessary?
• Is tethering supported?
• Can you add charges or extend the period?
• When will you start using it?

For compatible devices, please check the list of eSIM-compatible devices.

When to set up the Japanese eSIM?

If you want to use the internet immediately after arriving in Japan, it is recommended to install the eSIM before departure.

The general flow is as follows:

1. Purchase the Japanese eSIM before departure
2. Check the conditions for starting use
3. Connect to a stable Wi-Fi
4. Scan the QR code to add the eSIM
5. Change the line name to "Study Abroad in Japan" or "Japan eSIM"
6. Keep the line OFF until you arrive in Japan
7. Turn ON the eSIM after arriving in Japan
8. Select the Japanese eSIM for mobile data communication
9. Set up data roaming according to the product instructions
10. Turn OFF Wi-Fi and check the communication

Depending on the product, the usage period may start from the time of installation.

Please check the usage conditions of the product purchased before setting it up.

For detailed setup instructions, please refer to the eSIM setup guide.

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If the eSIM does not connect after arriving in Japan

If you have activated the Japanese eSIM but cannot connect, please check the following items:

• Is the Japanese eSIM line ON?
• Is the Japanese eSIM selected for mobile data communication?
• Is data roaming ON if necessary?
• Is the APN set correctly?
• Is it the start date for use?
• Is there remaining data capacity?
• Is the network selection set to automatic?
• Is the device's SIM lock removed?

After checking the settings, try turning airplane mode ON and then OFF, or restart your smartphone.

Even if you cannot connect, do not delete the eSIM immediately on your own judgment.

The QR code for travel or short-stay eSIMs may only be usable once. Deleting it may prevent reinstallation.

For detailed troubleshooting methods, please refer to troubleshooting for when the Japanese eSIM does not connect.

How to save data capacity during long-term studies

Use Wi-Fi at school or in the dormitory

Perform online classes, watch videos, update apps, and back up photos while connected to Wi-Fi at school or in the dormitory.

Lower the video quality

YouTube and video streaming services can consume a lot of data depending on the video quality.

Change to low or standard quality while using mobile communication.

Turn off automatic backup for photos and videos

Automatic uploads via iCloud or Google Photos can consume a large amount of data.

Save offline maps

Saving maps of the school, dormitory, and nearby stations while connected to Wi-Fi can reduce data usage while moving.

Prioritize Wi-Fi for online classes

Long online classes or video calls use a lot of data.

If you use mobile communication, turning off the camera can help reduce data usage.

Be cautious of automatic communication when tethering

When tethering your computer, OS updates or cloud synchronization may start automatically.

Stop unnecessary updates or synchronization before connecting.

If you run out of data capacity during long-term studies

If your data capacity is running low, first check the remaining amount and expiration date on the eSIM service's My Page or similar.

If additional charges are supported, you can add data to the same eSIM.

If not, connect to Wi-Fi at school, dormitory, or hotel, and purchase a new Japanese eSIM.

When adding a new eSIM, do not delete the current eSIM immediately; keep the line OFF and leave it as is.

Points to note when using Japanese eSIM for long-term studies

Costs may increase for long-term use

Purchasing short-term eSIMs every month may result in higher total costs than a Japanese monthly SIM.

If staying for more than three months, compare the total costs for long-term use.

There may be no Japanese phone number attached

With data-only eSIMs, you typically cannot receive regular calls from schools or part-time job locations.

SMS verification may not be supported

For services requiring SMS verification using a Japanese phone number, a data-only eSIM may not be usable.

Contracts requiring address verification or identity verification may exist

When switching to a Japanese monthly SIM, you may be asked for a residence card, address, and payment method.

Even unlimited plans may have speed restrictions

Even eSIMs labeled as unlimited may have high-speed data limits or fair usage policies in place.

Deleting the eSIM may prevent reuse

Even if communication troubles occur, do not delete the eSIM before contacting support.

Who should consider using eSIM for studying in Japan?

• Those who want to use the internet immediately after arriving in Japan
• Those studying for a short term of 1 week to 3 months
• Those who want to communicate until their Japanese mobile contract is completed
• Those who do not want to swap physical SIM cards
• Those who want to maintain their overseas main line
• Those who do not need a Japanese phone number immediately
• Those who can use Wi-Fi at school or in the dormitory

Who should consider using a Japanese monthly SIM?

• Those staying in Japan for six months or more
• Those who need a Japanese phone number
• Those planning to work part-time or have a job
• Those who will use a lot of data each month
• Those who want to keep long-term communication costs down
• Those who will use SMS verification for Japanese services

Frequently asked questions about eSIM for studying in Japan

I will study in Japan for a year; can I live with just eSIM?

You can use it for data communication only.

However, you may need a Japanese phone number for schools, banks, part-time jobs, and deliveries. For long-term studies, also compare SIMs with phone numbers or monthly SIMs.

How many GB do I need for a one-month study?

If you primarily use Wi-Fi at school or in the dormitory, around 3 to 10GB is a good estimate.

If you frequently use SNS or video calls, consider 10 to 20GB or more; for online classes or tethering, consider a large capacity plan.

Is a Japanese phone number included?

Most travel or short-stay eSIMs are data-only and do not include a Japanese phone number.

Can I use LINE with eSIM?

If you can connect to the internet, you can use LINE for messaging, voice calls, and video calls.

If I work part-time during my studies, will I need a phone number?

It varies by employer and job type, but you may be asked for a Japanese phone number as a contact.

Can I switch from eSIM to a monthly SIM after arriving in Japan?

Yes, you can switch.

Confirm the connection of the monthly SIM before turning OFF the Japanese eSIM.

Can I keep my overseas phone number while using this?

If you have a dual SIM-compatible device, you may be able to keep your overseas main line and use the Japanese eSIM for data communication.

Can I tether with the Japanese eSIM?

You can use tethering if the product and smartphone support it.

Check the tethering conditions and capacity limits before purchasing.

Is it okay to purchase the Japanese eSIM every month?

You can purchase it, but you need to consider the total monthly costs and the hassle of setup.

For long-term stays, a monthly SIM may be easier to use.

If I cannot connect, should I delete the eSIM?

Do not delete it.

Check the settings, APN, data roaming, and start date, and if it still does not improve, contact support.

For other questions, please refer to frequently asked questions about eSIM.

Conclusion | Use eSIM for short-term studies, and compare plans with phone numbers for long-term studies

You can use Japanese eSIM for studying in Japan if you have a compatible smartphone.

You can prepare it online before arriving in Japan, allowing you to check maps, transfer guides, translations, and school communications immediately after arriving at the airport.

It is especially convenient as a means of communication for short-term studies or until your Japanese mobile phone contract is completed.

When choosing a means of communication, check the following items:

• Validity period suitable for your study duration
• Data capacity needed per month
• Whether a Japanese phone number or SMS is needed
• Whether tethering will be used
• Whether additional charges or extensions are supported
• Total costs for long-term use
• Support system

For short-term studies of about 1 week to 3 months, the Japanese eSIM is likely to be easy to use.

For long-term studies of six months or more, since you may need a Japanese phone number for schools, banks, and part-time jobs, please also compare eSIMs with phone numbers and monthly SIMs.

You can check the currently available plans for Japan at Japan eSIM products and pricing plans.

If you want to compare capacity and usage periods, please refer to comparison of Japan eSIM pricing and plans.