Updated: 2025-11-18 17:06:20
Stable communication is essential for a smooth, short-term business stay in Japan. During busy schedules, you will often need to check emails, join online meetings, and use map applications. While Pocket WiFi is the most stable means of communication during your stay in Japan, eSIMs have recently grown in data capacity and improved in communication quality. eSIMs can be purchased anytime, anywhere. This saves you the hassle of stopping by the airport or a store, allowing you to start using service immediately upon arrival. Furthermore, since everything is handled by a single smartphone, there is no need to carry extra devices.
Many people are likely looking for an eSIM that works in Japan.
If you are considering purchasing an eSIM for business communication in Japan, you might be concerned about data capacity and price, but you should also fully understand its features. In particular, the ability to use the tethering (HOTSPOT) feature without restriction to connect your laptop or tablet is important for business advantage.
This article will introduce the features of Japanese eSIMs and the selection criteria essential for stable business communication.
When choosing an eSIM for work, not only "data capacity" but also "stability" and "speed" are most critical. You must check the following points, especially if you plan to use large data transfers or hold online meetings.
Most local eSIMs in Japan utilize the network of a major domestic telecommunications carrier. Our eSIM uses the docomo network, which boasts the largest coverage and stability in Japan, enabling you to conduct business without interruption while traveling or at your destination.
Business use often involves frequent sending and receiving of large files and long video conferences, not just email checks.
Especially when connecting laptops or tablets via tethering (HOTSPOT), data consumption increases significantly compared to smartphone-only use.
Short-term stay eSIM plans (and SIM cards) do not allow voice calls. Phone numbers and SMS are generally only available to residents of Japan. Prepaid SIM cards and eSIMs sold for short-term visitors to Japan are strictly for data communication.
If you need to make calls in Japan, set up an IP phone before coming to Japan.
SIM cards with SMS are available for purchase here.
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Some eSIMs sold outside of Japan can be used in Japan.
These eSIMs communicate via roaming. This means that while you are in Japan, your communication is routed through a country like China or Singapore.
While this might not be noticeable when using your smartphone, you may find that websites load slowly or some websites are partially inaccessible. Furthermore, there are roaming-specific restrictions, such as the inability to use tethering (HOTSPOT).
Business Risks
When used for work, roaming eSIMs raise concerns regarding security and stability. Communication routed through overseas carriers can lead to connection instability, prevent the use of corporate VPNs, or severely slow down communication speeds.
Local Japanese eSIMs do not have restrictions that prevent viewing websites.
Also, many eSIMs, such as the eSIM provided by CDJapan Rental, do not impose restrictions on tethering.
If you are purchasing an eSIM to use during a business stay in Japan, a local Japanese eSIM is recommended.
If you plan to use your smartphone as a hotspot, be sure to choose an eSIM that does not restrict tethering.
When staying in Japan for work, there may be times when stable internet access is not available in your work environment.
While it is possible to insert an eSIM into your smartphone and use the internet via tethering, if you intend to use the internet for serious work, Pocket WiFi is better suited than an eSIM.
Pocket WiFi is a device specifically designed to enable communication for multiple devices, allowing you to connect various devices like laptops and smartphones to the internet. Furthermore, Pocket WiFi encrypts communication content, so you don't have to worry about security.
Most Pocket WiFi devices use the networks of major telecommunications carriers, providing good, stable communication quality. Since they are designed to connect multiple devices like laptops and smartphones, they typically come with large data plans and long battery life. Furthermore, Pocket WiFi encrypts communication content, so you don't have to worry about security.
| Comparison Item | eSIM (Tethering) | Pocket WiFi |
|---|---|---|
| Convenience & Ease of Use | ◎ (Only requires a smartphone) | △ (Requires carrying and charging a device) |
| Security | △ (Requires security measures when using tethering) | ◎ (Dedicated device allows encrypted communication) |
| Stability & Speed | △ (Prone to instability with prolonged use or large data transfers) | ◎ (Stable communication even with multiple devices) |
| Battery | × (Significant drain on the host smartphone's battery) | ◎ (Can be used continuously for a long time) |
| Team Use | × (Intended for individual use) | ◎ (Can be shared among multiple people) |
The greatest advantage of eSIM is its ease of use. If you complete the setup before arriving in Japan, you can start communicating immediately after landing.
It is essential to ensure you have internet access during your business stay in Japan.
eSIMs are easy to purchase, but when used in Japan, a local Japanese eSIM on the docomo network without tethering restrictions is recommended.
However, if you need to connect many devices to the internet, an eSIM alone may be insufficient. In that case, you should rent Pocket WiFi.
