Dual SIM functionality allows you to use two different SIM cards on a single smartphone, potentially saving on communication costs and improving usability.
Below, we will explain how to use dual SIM and the features of major mobile carriers (in Japan) in an easy-to-understand manner.
Dual SIM functionality allows you to use two different SIM cards on a single smartphone, potentially saving on communication costs and improving usability. Below, we will explain how to use dual SIM and the features of major mobile carriers (in Japan) in an easy-to-understand manner.
Main uses of dual SIM
[1] Separating voice calls and data communication
Voice: Major carrier (high call quality)
Data communication: Low-cost SIM (cheap data charges)
Example
Voice: Docomo (or ahamo)
Data: IIJmio, Rakuten Mobile, etc.
[2] Separate work and personal use
- Use two phone numbers on one smartphone
- Use the work SIM during work hours, and switch to the personal SIM after work hours.
[3] Using different SIMs for overseas and domestic use
- Use an overseas SIM (purchased locally) and a Japanese SIM together
- Convenient for overseas business trips and travel. You can also retain your Japanese phone number.
[4] Covering weak signal areas (area supplementation)
- Rakuten Mobile (some areas have weak signal) + backup with another carrier
- Even if Rakuten is out of range, you can still communicate with another SIM.
