Dual SIM is a convenient feature that allows you to use two SIM cards on a single smartphone. By flexibly switching between them for various purposes—such as work and personal use, or data communication and calls—you can save on communication costs and improve convenience.
This page focuses specifically on the combination of MNOs (MNO sub-brands) and MVNOs (low-cost SIMs), introducing their benefits and specific combination examples. Find the perfect dual SIM strategy for you and enjoy a smarter mobile life!
Why is the combination of an MNO (or a sub-brand of an MNO) and a low-cost SIM the optimal choice?
MNOs (Mobile Network Operators) are major carriers that own their own communication infrastructure (Docomo, au, SoftBank, Rakuten Mobile). MNO sub-brands are low-cost brands offered by MNOs (ahamo, povo, LINEMO, UQ mobile, Y!mobile). On the other hand, MVNOs (Mobile Virtual Network Operators) are providers that lease network lines from MNOs to offer services.
By combining these two, you can take advantage of the best aspects of each and create a very well-balanced dual-SIM environment.
Advantages of MNOs (sub-brands of MNOs)
Stable, high-speed communication: Provides stable communication quality over a wide area. Easy to connect not only in urban areas but also in rural areas.
- High-quality calls: Stable call quality ensures reliable communication even in emergencies.
- Comprehensive support: Access to in-store support and attentive customer service.
- Carrier billing and carrier email: Often includes convenient supplementary services.
Advantages of budget SIM cards
Unbeatable low prices: Data communication fees are significantly cheaper compared to MNOs.
- Diverse pricing plans: Easy to choose a data capacity that suits you, from light users to heavy users.
- No-commitment plans: Many plans have no contract period commitment, making it easy to switch providers.
Benefits of combining them
Significant savings on communication costs: By using a low-cost SIM for the majority of your data communication, you can reduce your monthly fees.
- Ensuring communication quality: You can ensure stable quality for calls and important communications with an MNO (sub-brand).
- Flexible usage tailored to your needs: You can use separate numbers for work and personal use, or separate lines for data communication and calls, allowing for flexible usage.
- Preparedness in case of disaster: Even if one line is unreliable, the other line may still be usable, providing risk diversification.
Combination Examples: Find the perfect plan for you!
Here, we’ll introduce several specific examples of combinations between MNOs (or their sub-brands) and low-cost SIM cards.
Try to find the best combination for you based on your usage and priorities.
Recommended Plan Example [1]:
Save drastically on calls with an MNO and data with a low-cost SIM!
povo2.0 (main line) x IIJmio (secondary line)
povo2.0
Usage: Major phone numbers, calls (unlimited calling options, etc.), emergency communication
Basic fee is 0 yen; purchase toppings only when needed. Combine with call toppings (e.g., unlimited calls within 5 minutes).
IIJmio (Giga Plan)
Usage: Data communication (web browsing, SNS, video viewing, etc.)
Choose from a wide range of data capacities, such as 2GB from 850 yen, 5GB from 990 yen, 10GB from 1,500 yen, etc.
Recommended for:
Those who make many calls, those who use calls for work, those who use data communication moderately but want to keep costs down, and those who prioritize stable communication quality.
Recommended plan example [2]:
A good balance with a sub-brand of an MNO, and a budget SIM for a backup line or to add extra data!
ahamo (main line) x povo2.0 (secondary line)
ahamo
Usage: Main phone number, data communication, calls
20GB of data and unlimited calls within 5 minutes for ¥2,970 per month (tax included). Data can be increased up to 100GB for an additional fee.
povo2.0
Usage: Backup line, additional data when needed, use of specific services (e.g., data-only SIM)
Purchase data top-ups only when needed. Useful during disasters or when the main line is down.
Recommended for:
Those who usually find their main line sufficient but sometimes want to use data without worrying about limits.
Those who want to secure a means of communication in emergencies such as disasters.
Those who want to reduce data consumption for specific apps or services.
Recommended plan example [3]:
Use separate phone numbers for work and personal use!
docomo, au, Softbank basic plan (main line) x Rakuten Mobile (secondary line)
Basic plans from docomo, au, and Softbank
Usage: Work or main phone number, stable communication, security-focused
Rakuten Mobile’s strongest plan
Usage: Private phone number, data communication, SNS
Monthly fee from 968 yen (tax included). Unlimited data for a maximum of 3,278 yen (tax included) per month, but calls are free with Rakuten Link. Since it becomes cheaper in months with low data usage, it’s worth considering even if you primarily use it for free calls.
Rakuten Mobile (less than 3GB usage) becomes effectively free with increased Rakuten Ichiba points.
Recommended for:
Those who make many calls or use calls for work.
Those who use a moderate amount of data but want to keep costs down.
Those who want to use specific apps or services at a discount.
Dual SIM setups using an MNO (or a sub-brand of an MNO) and a low-cost SIM are an extremely effective way to save on communication costs while also improving convenience. Find the perfect combination to suit your lifestyle and make smart use of your smartphone!
