Many people may find the communication fees of Japan's three major carriers too high and are considering switching to more cost-effective budget SIM cards (Japanese: 格安SIM). However, with a wide variety of options like ahamo, povo, Rakuten Mobile, and UQ mobile, each offering different data allowances and pricing, it's natural to have questions: "Are budget SIM cards reliable despite being cheap?" "Will I regret switching to a Japanese budget SIM card?"

In this article, we will comprehensively compare and evaluate 15 popular budget SIM card services from multiple perspectives, including virtual operators like mineo and IIJmio, as well as budget SIM plans offered by major carriers.

Known as "MVNOs," budget SIM cards utilize the networks of the three major carriers (NTT Docomo, au, SoftBank). In the past, their communication speeds could be unstable during certain times, but after years of development, many brands have become highly cost-effective, making them the preferred mobile card choice for many foreigners in Japan.

Among the budget SIMs with stable communication speeds and affordable prices, such as ahamo, povo, and LINEMO, povo is the cheapest for monthly data usage of 3GB, 20GB, and 50GB. Its unique feature is the absence of a fixed monthly plan; instead, users purchase data as needed. By buying three months' worth of data at once, it becomes cheaper than other carriers.

Table of Contents show

How to Choose a Budget SIM Card

Below, we outline the "4 key points" to confirm when choosing a budget SIM card.

1. Recommended: Budget SIMs from Major Carriers with Excellent Speed and Stability

Budget SIMs that offer both fast communication speeds and reliable signal connectivity are MNOs (Mobile Network Operators) using the networks of the three major carriers: NTT Docomo, au, and SoftBank.

MNOs like povo, LINEMO, ahamo, UQ mobile, Y!mobile, and irumo use the same networks as the major carriers, ensuring stable signal connections and consistently fast communication speeds. In contrast, MVNO (Mobile Virtual Network Operator) budget SIMs, which use only parts of the major carriers' networks, may have good signal connectivity but tend to slow down during network congestion. During peak hours like 12:00-13:00, many MVNOs' speeds drop below 10Mbps, making video loading times longer.

As the fourth major carrier, Rakuten Mobile offers good communication speeds, but its weak signal connectivity in underground or indoor locations is a drawback.

When comparing monthly fees for 3GB usage, MVNO budget SIMs are cheaper. However, considering their drawbacks, we recommend choosing MNOs that balance communication speed and signal stability.

2. Choose the Most Cost-Effective MNO Plan for Your Data Needs

After narrowing down to MNOs with both speed and signal reliability, focus on price comparisons for budget SIMs. The ideal budget SIM depends on your smartphone usage habits and data needs. Below, we explain which budget SIM suits different user types.

Among the six MNOs, povo, LINEMO, and ahamo offer low prices and large data plans. Choose a plan that is both affordable and meets your data requirements based on your usage habits.

For users mainly browsing websites and social media, occasionally watching videos, we recommend povo's 3GB plan, which is priced affordably. Its unique feature is the absence of a fixed monthly fee, allowing users to purchase data as needed. LINEMO's 3GB plan is also priced at 990 yen, but it uses a tiered system where exceeding 3GB incurs a 2,090 yen charge for 10GB, potentially doubling costs if you're not careful. Thus, we recommend prioritizing povo, which avoids automatic fee increases.

For users who heavily watch videos or play online games without WiFi, povo is also recommended. For 20GB monthly usage, you can purchase the 6,490 yen "60GB/90 days" plan, equivalent to 2,163 yen per month for 20GB, the cheapest among MNOs. For users without home WiFi and needing more than 20GB, the 9,834 yen "300GB/90 days" plan equates to 100GB per month for just 3,278 yen, highly cost-effective.

povo's unique aspect is that users must purchase data via the app when it runs out or expires, and it supports bulk purchases for several months, differing from other budget SIMs. If you find on-demand data purchases inconvenient or dislike bulk buying, consider ahamo or LINEMO.

Additionally, LINEMO, povo, and ahamo are cheaper than Y!mobile, UQ mobile, and irumo because they only support online applications without physical store support. Contracting, setup, and activation must be done independently, but the process is straightforward. If you're concerned about completing it alone and prefer support, consider Y!mobile, UQ mobile, or irumo.

3. Recommended: Budget SIMs Supporting eSIM with Simple Activation

Budget SIMs come in two types: eSIMs, downloaded onto smartphones, and physical SIM cards inserted into devices. We recommend choosing budget SIMs that support eSIMs, as they allow quick activation after signing up.

eSIMs can be set up by scanning a QR code displayed after signing up or sent via email, enabling instant activation with a simple process. In contrast, physical SIM cards typically take 3 to 7 days to be delivered after signing up.

Nowadays, some MVNOs only support physical SIM cards, but an increasing number of budget SIMs are supporting eSIMs.

4. Avoid Purchasing Budget SIMs Bundled with iPhone or Android Smartphones

Among users considering switching to budget SIMs, some may also plan to replace their smartphones. If you need to buy a smartphone, we recommend avoiding bundled packages with budget SIMs.

Although some companies offer budget SIMs bundled with smartphones, this purchasing method is generally not recommended. The smartphones offered in these bundles, whether iPhone or Android, are mostly older models. For example, at UQ Mobile, bundled iPhones are limited to iPhone 14, 15, and 16e, with the latest iPhone 16 or 16 Pro unavailable. Android smartphones also often lack high-performance models, which may leave users dissatisfied. Moreover, the prices are not necessarily cheap, making them less cost-effective overall.

Japan Budget SIM Card Recommended Popularity Ranking

1st Place: povo

Official Website

https://povo.jp/

Network Used

Network: au network
Network Type: MNO
eSIM Support: Yes
MNP One-Stop Porting: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	990
2-3GB	990
4-10GB	2,163
11-20GB	2,163
21-30GB	2,780
50GB or more	3,278

Features

Suitable For: All users from low to high data needs, ideal as a secondary SIM
Advantages:
Base monthly fee of 0 yen, using an on-demand data "topping" model
Wide range of plans, from 1GB to unlimited data
Uses au network, with excellent communication speed and signal stability
Disadvantages:
No physical stores or phone support, requires online contracting
Termination enforced after 6 months of no plan purchases

Available Plans

1GB/7 days, 3GB/30 days, 20GB/30 days, 30GB/30 days, 60GB/90 days, 300GB/90 days, etc.

Communication Speed

Lunch Break (12:00-13:00): 197.1Mbps
Regular Hours (14:00-16:00): 351.9Mbps
Commute Hours (17:00-19:00): 337Mbps

Call Charges

5-Minute Free Calls: Available
Unlimited Calls: Available
Basic Call Rate: 22 yen/30 seconds

Detailed Introduction

au's online-exclusive plan "povo" is suitable for users who mainly browse websites with low data usage, as well as those who watch videos or play games for extended periods, allowing flexible data customization based on usage habits.

povo's biggest feature is its 0 yen base monthly fee, using an on-demand purchase model. Plans range from ultra-small 1GB to large-capacity 300GB or unlimited. Especially for users needing over 20GB, the 9,834 yen (300GB/90 days) three-month plan offers excellent value.

povo uses the same network as au, achieving speeds far exceeding the 25Mbps required for HD video playback even during congested lunch hours (12:00-13:00), outperforming MVNOs with remarkable stability. Signal connectivity is also highly reliable, enabling smooth HD video streaming or app downloads at any time.

As an online-exclusive brand, povo lacks physical store or phone support, requiring contracting via a dedicated app. However, its interface is intuitive, suitable for beginners, and supports eSIM, making porting straightforward.

With a 0 yen base fee, povo is an excellent secondary SIM choice for users whose primary SIM is not on the au network. Note that if no plan is purchased for 6 consecutive months, the contract will be forcibly terminated. Whether switching to a budget SIM or adding a secondary SIM for a primary SIM with poor signal, povo is a highly recommended plan.

2nd Place: irumo

Official Website

https://irumo.docomo.ne.jp/

Network Used

Network: NTT Docomo network
Network Type: MNO
eSIM Support: Yes
MNP One-Stop Porting: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	2,167
2-3GB	2,167
4-10GB	2,827
11-20GB	No plan
21-30GB	No plan
50GB or more	No plan

Features

Suitable For: Users wanting NTT Docomo physical store support with small to medium data needs
Advantages:
Offers support equivalent to major carriers
1,100 yen monthly discount for users with NTT Docomo fiber or Docomo Home
Maintains high-speed communication during lunch hours
Disadvantages:
Base monthly fee is higher compared to other budget SIMs
Possible speed restrictions during network congestion

Available Plans

0.5GB, 3GB, 6GB, 9GB

Communication Speed

Lunch Break (12:00-13:00): 732.5Mbps
Regular Hours (14:00-16:00): 520.5Mbps
Commute Hours (17:00-19:00): 614Mbps

Call Charges

5-Minute Free Calls: Available
Unlimited Calls: Available
Basic Call Rate: 22 yen/30 seconds

Detailed Introduction

NTT Docomo's budget plan "irumo" is positioned similarly to au's "UQ mobile" and SoftBank's "Y!mobile," offering equivalent support to major carriers at a lower price.

irumo's data plans range from 0.5GB to 9GB, targeting small to medium data users. Its flagship 3GB plan costs 2,167 yen per month, which is higher than other budget SIMs. However, users with "NTT Docomo fiber" or "Docomo Home" can enjoy a 1,100 yen monthly discount, and setting up d-card payments adds an extra 187 yen monthly discount.

irumo uses the same network as NTT Docomo, with network quality comparable to carrier plans, though the official site notes possible speed restrictions during congestion. Still, tests show that even during the most congested lunch hours (12:00-13:00), irumo maintains speeds for smooth HD video streaming and fast app downloads.

irumo's biggest advantage is its support for NTT Docomo physical store contracting and customer service. For users wanting a budget SIM but concerned about support, irumo is a strong choice, offering lower fees with carrier-level support.

3rd Place: UQ Mobile

Official Website

https://www.uqwimax.jp/mobile/

Network Used

Network: au network
Network Type: MNO
eSIM Support: Yes
MNP One-Stop Porting: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	2,365
2-3GB	2,365
4-10GB	2,915
11-20GB	3,278
21-30GB	3,278
50GB or more	No plan

Features

Recommended For: Users needing stable speeds and comprehensive support, especially those eligible for the "Home Bundle Discount"
Advantages:
Communication quality equivalent to au
Wide range of WiFi services eligible for the "Home Bundle Discount"

Available Plans

4GB, 15GB, 33GB

Communication Speed

Lunch Break (12:00-13:00): 475.5Mbps
Regular Hours (14:00-16:00): 374.7Mbps
Commute Hours (17:00-19:00): 367.7Mbps

Call Charges

10-Minute Free Calls: Available
Unlimited Calls: Available
60-Minute Monthly Free Calls: Available
Basic Call Rate: 22 yen/30 seconds

Detailed Introduction

As a sub-brand of au, "UQ Mobile" is popular for offering au-equivalent communication quality at lower costs. Its plans cover 4GB to 33GB, with three options. The cheapest 4GB plan costs 2,365 yen per month, slightly high, but the "Home Bundle Discount" offers a 1,100 yen monthly discount. With a wide range of eligible WiFi services, users should check if their home WiFi qualifies for the discount. Even without the discount, the 33GB plan at 3,278 yen remains competitive.

As an MNO using the au network, UQ Mobile's communication speed is minimally affected by time slots. Even during congested lunch hours (12:00-13:00), speeds exceed 25Mbps, sufficient for smooth HD video streaming or fast app downloads.

Support and contracting at au stores nationwide is another major advantage. Although au store signs may not display the UQ Mobile logo, windows prominently indicate "UQ Mobile Authorized Store."

4th Place: ahamo

Official Website

https://ahamo.com/

Network Used

Network: NTT Docomo network
Network Type: MNO
eSIM Support: Yes
MNP One-Stop Porting: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	2,970
2-3GB	2,970
4-10GB	2,970
11-20GB	2,970
21-30GB	2,970
50GB or more	4,950

Features

Recommended For: Users needing large data amounts
Advantages:
Uses NTT Docomo network, maintaining stable speeds during congestion
Offers large-capacity plans suitable for 100GB+ usage
Disadvantages:
No small-capacity plans, unsuitable for users not consuming full data
Support at NTT Docomo stores requires an additional 3,300 yen fee

Available Plans

30GB, 110GB

Communication Speed

Lunch Break (12:00-13:00): 741.5Mbps
Regular Hours (14:00-16:00): 774.5Mbps
Commute Hours (17:00-19:00): 587.5Mbps

Call Charges

5-Minute Free Calls: Included in plans
Unlimited Calls: Available
Basic Call Rate: 22 yen/30 seconds

Detailed Introduction

Launched by NTT Docomo in March 2021, the budget SIM card "ahamo" offers a single plan: 30GB for 2,970 yen per month. For more data, users can add the "ahamo Large Option" for an extra 1,980 yen, increasing the capacity to a maximum of 110GB. With no small-capacity plans, users who don't use their full data should consider other budget SIMs.

ahamo uses the same network as NTT Docomo, with speeds resilient to network congestion. Even during the most congested lunch hours (12:00-13:00), speeds exceed 300Mbps, allowing comfortable enjoyment of entertainment content at any time.

ahamo generally does not support contracting or assistance at NTT Docomo physical stores, but users can pay a one-time 3,300 yen fee for contracting support. We recommend trying the process independently first, opting for paid support if it feels challenging.

5th Place: LinksMate

Official Website

https://www.linksmate.jp/

Network Used

Network: NTT Docomo network
Network Type: MVNO
eSIM Support: Yes
MNP One-Stop Porting: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	737
2-3GB	902
4-10GB	1,210
11-20GB	2,310
21-30GB	2,970
50GB or more	4,279

Features

Recommended For: Users who watch videos or play games and want to save data with the "Count-Free Option"
Advantages:
Wide range of plans, from 0.1GB to 1.5TB
"Count-Free Option" reduces data consumption for specific services to 1/10
Disadvantages:
Plans above 20GB are priced higher than market average

Available Plans

0.5GB, 1GB, 2GB, 3GB, 4GB, 5GB, 15GB, 21GB, 51GB, etc.

Communication Speed

Lunch Break (12:00-13:00): 339.5Mbps
Regular Hours (14:00-16:00): 232.5Mbps
Commute Hours (17:00-19:00): 303.5Mbps

Call Charges

10-Minute Free Calls: Available
Basic Call Rate: 11 yen/30 seconds with MatePhone app, 22 yen/30 seconds without app

Detailed Introduction

"LinksMate" is a budget SIM particularly suitable for users who heavily use video streaming services or games.

LinksMate offers an extensive range of plans, from 0.1GB to 1.5TB, catering to various needs. The 3GB plan costs only 902 yen per month, making it affordable, but plans above 20GB are relatively expensive, less suitable for high-data users.

Speed tests show that even during congested lunch hours (12:00-13:00), LinksMate supports smooth HD video streaming. However, as it uses parts of the NTT Docomo network, there may be slight delays in loading websites or videos compared to MNOs using the full network.

LinksMate's unique feature is the "Count-Free Option." For an additional 550 yen per month, data consumption for services like "ABEMA," "U-NEXT," "Instagram," and "X (Twitter)" is reduced to 1/10. Users can save significantly by choosing smaller plans with this option. For users who frequently watch videos, play games, or accept minor speed fluctuations for lower prices, LinksMate is highly attractive.

6th Place: Y!mobile

Official Website

https://www.ymobile.jp/

Network Used

Network: SoftBank network
Network Type: MNO
eSIM Support: Yes
MNP One-Stop Porting: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	2,365
2-3GB	2,365
4-10GB	2,915
11-20GB	4,015
21-30GB	4,015
50GB or more	No plan

Features

Recommended For: Users with SoftBank Fiber or SoftBank Air eligible for bundle discounts
Advantages:
Uses SoftBank network with stable connectivity
Supports HD video playback speeds across all time slots
Over 2,000 stores in Japan provide comprehensive support
Disadvantages:
Overall fees are relatively high
Discounts limited to users with SoftBank Fiber or SoftBank Air

Available Plans

4GB, 30GB, 35GB

Communication Speed

Lunch Break (12:00-13:00): 241.2Mbps
Regular Hours (14:00-16:00): 189.9Mbps
Commute Hours (17:00-19:00): 387.5Mbps

Call Charges

10-Minute Free Calls: Available
Unlimited Calls: Available
Basic Call Rate: 22 yen/30 seconds

Detailed Introduction

"Y!mobile," a SoftBank sub-brand, uses the SoftBank network, offering services at lower costs than carrier plans, positioned as a budget sub-brand.

Since January 2025, Y!mobile has added large-capacity plans, offering 4GB, 30GB, and 35GB options. The 4GB plan costs 2,365 yen per month, relatively high, but users with "SoftBank Fiber" or "SoftBank Air" can enjoy discounts of 1,100 to 1,650 yen per month, making fees more competitive.

Y!mobile uses the same network as SoftBank, maintaining comfortable communication speeds even during congested periods. Tests show speeds far exceeding 25Mbps during lunch hours (12:00-13:00), with minimal fluctuations, allowing smooth enjoyment of entertainment content at any time.

Y!mobile's bundle discounts significantly reduce costs, making it a high-quality budget SIM choice for users eligible for "SoftBank Fiber" or "SoftBank Air" discounts, balancing speed, support, and value.

7th Place: Rakuten Mobile

Official Website

https://network.mobile.rakuten.co.jp/

Network Used

Network: Rakuten proprietary network + au partner network
Network Type: MNO
eSIM Support: Yes
MNP One-Stop Porting: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	1,078
2-3GB	1,078
4-10GB	2,178
11-20GB	2,178
21-30GB	3,278
50GB or more (Unlimited)	3,278

Available Plans

3GB, 20GB, Unlimited

Communication Speed

Lunch Break (12:00-13:00): 37.7Mbps
Regular Hours (14:00-16:00): 54.9Mbps
Commute Hours (17:00-19:00): 41.6Mbps

Call Charges

5-Minute Free Calls: Available
60-Minute Free Calls: 15-minute free calls / Unlimited calls (requires Rakuten Link app)
Basic Call Rate: 0 yen (with Rakuten Link), 22 yen/30 seconds (without app)

Detailed Introduction

"Rakuten Mobile," part of Rakuten's extensive internet-related services, began operating as an MNO in April 2020, using its own base stations and network. In areas where Rakuten's network is not fully developed, it uses au's network as a partner network to cover service areas.

Rakuten SIM offers a single plan with tiered pricing based on data usage: 1,078 yen per month for 3GB, 2,178 yen for 20GB, relatively affordable. Most notably, usage exceeding 20GB costs 3,278 yen per month for unlimited data, with no cap. Few budget SIM providers offer unlimited plans, making this highly attractive.

However, Rakuten SIM's biggest drawback is its weaker signal connectivity compared to other carriers. Signal connectivity remains poor in some underground stores. Thus, if used as a primary line, we recommend pairing it with another budget SIM as a secondary line.

8th Place: LINEMO

Official Website

https://www.linemo.jp/

Porting from other carriers: Receive 20,000 yen in PayPay points
New contract: Receive 10,000 yen in PayPay points
PayPay points cannot be withdrawn or transferred, usable at PayPay official stores or PayPay Card official stores
Promotions may end or change at any time

Network Used

Network: SoftBank network
Network Type: MNO
eSIM Support: Yes
MNP One-Stop Porting: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	990
2-3GB	990
4-10GB	2,090
11-20GB	2,970
21-30GB	2,970
50GB or more (Unlimited)	No plan

Features

Recommended For: Users with sufficient 3GB usage or those resistant to povo's on-demand purchase model
Advantages:
LINE usage does not consume data
Uses SoftBank network with excellent communication speed
Disadvantages:
Tiered plan structure, exceeding 3GB doubles fees
No physical store support

Available Plans

3GB or less, 10GB or less, 30GB or less

Communication Speed

Lunch Break (12:00-13:00): 266.4Mbps
Regular Hours (14:00-16:00): 227.1Mbps
Commute Hours (17:00-19:00): 355.6Mbps

Call Charges

5-Minute Free Calls: Available
Unlimited Calls: Available
Basic Call Rate: 22 yen/30 seconds

Detailed Introduction

SoftBank's online-exclusive brand "LINEMO" is ideal for users with sufficient 3GB data needs. It offers fast communication speeds, low prices, and data-free LINE usage, providing excellent value.

LINEMO uses the same network as SoftBank, delivering outstanding communication speed. Even during congested lunch hours (12:00-13:00), it supports smooth HD video streaming with stable signal connectivity.

The "LINEMO Best Plan" uses tiered billing, with fees determined by 3GB to 10GB usage; there's also the "LINEMO Best Plan V" for up to 30GB. The 3GB plan costs just 990 yen per month, but exceeding 3GB triggers a 2,090 yen charge for 10GB.

Unfortunately, LINEMO lacks physical store support, but its fees are lower than carrier plans, and online chat support resolves issues quickly. It supports eSIM, making porting simple. For users with 3GB needs or preferring stable networks, LINEMO is a great choice.

9th Place: mineo

Official Website

https://mineo.jp/

Network Used

Network: NTT Docomo network, au network, SoftBank network
Network Type: MVNO
eSIM Support: Yes (except SoftBank network)
MNP One-Stop Porting: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	1,298
2-3GB	1,518
4-10GB	1,518
11-20GB	2,178
21-30GB	2,948
50GB or more	2,948

Features

Recommended For: Users wanting multiple network options or a secondary SIM
Advantages:
Option to choose NTT Docomo, au, or SoftBank networks
"Mysoku" low-speed unlimited plan suitable for music streaming and SNS
Disadvantages:
Except for the 50GB plan, other plans are relatively expensive
As an MVNO, speeds may be unstable depending on network or time

Available Plans

1GB, 5GB, 10GB, 20GB, 50GB

Communication Speed

Lunch Break (12:00-13:00):
NTT Docomo network: 407.5Mbps
au network: 158.4Mbps
SoftBank network: 188.9Mbps
Regular Hours (14:00-16:00):
NTT Docomo network: 507Mbps
au network: 136.5Mbps
SoftBank network: 231.9Mbps
Commute Hours (17:00-19:00):
NTT Docomo network: 476.5Mbps
au network: 312Mbps
SoftBank network: 205.3Mbps

Call Charges

10-Minute Free Calls: Available
Unlimited Calls: Available
Basic Call Rate: 22 yen/30 seconds (10 yen/30 seconds with dedicated app)

Detailed Introduction

Operated by Optage, a major telecom provider under Kansai Electric Power, "mineo" supports NTT Docomo, au, and SoftBank networks, offering 5G services.

mineo's plans are divided into two categories:

My Pita: Fixed monthly data plans from 1GB to 50GB. Since March 13, 2025, a competitive 50GB plan was added, but other plans are relatively expensive.
Mysoku: Low-speed unlimited plan with constant low speed but no data cap. The top 3Mbps "Premium" plan meets music streaming and SNS needs.

The "Mysoku" plan is mineo's unique highlight, ideal as a secondary SIM. The cheapest plan costs just 250 yen per month, with the flexibility to choose any of the three major networks, unrestricted by the primary SIM's network. However, its low-speed nature limits its use, so pairing it with a 24-hour unlimited data option (198 yen) can enhance speed for more scenarios.

mineo is favored for its flexibility in supporting three networks and the unique "Mysoku" low-speed unlimited plan, especially suitable as a secondary SIM or for users needing network choice. The 50GB plan is competitively priced, but others are costly, and MVNO characteristics may cause speed instability during congestion.

10th Place: J:COM MOBILE

Official Website

https://www.jcom.co.jp/service/mobile/

Network Used

Network: au Network
Network Type: MVNO
eSIM Support: Yes
MNP One-Stop Transfer Support: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	1,078
2-3GB	1,628
4-10GB	1,628
11-20GB	2,728
21-30GB	No Plan
50GB or more	No Plan

Features

Recommended For: Users already using J:COM services
Advantages:
If using J:COM services at home, the 5GB plan is only 1,078 yen/month
Provides comprehensive customer support
Disadvantages:
Overall costs are relatively high
As an MVNO, network speeds may be affected during congestion

Available Plans

1GB, 5GB, 10GB, 20GB

Network Speeds

Lunch Break (12:00-13:00): 8.9Mbps
Regular Hours (14:00-16:00): 120.1Mbps
Commute Hours (17:00-19:00): 392.4Mbps

Call Charges

5-Minute Free Calls: Available
60-Minute Free Calls: Available
Basic Call Rate: 22 yen/30 seconds

Detailed Overview

Launched by JCOM, a major player in the cable TV industry, “J:COM MOBILE” is an MVNO budget SIM using the au network, supporting 5G services at no additional cost.

J:COM MOBILE offers four plan options from 1GB to 20GB. While overall costs are relatively high, users with J:COM WiFi or TV services at home can get the 5GB plan for a discounted 1,078 yen/month, significantly improving cost-effectiveness.

Except during lunch hours (12:00-13:00), J:COM MOBILE’s speeds exceed the 25Mbps required for smooth HD video streaming.

J:COM MOBILE is ideal for users already using J:COM cable TV or WiFi services, with the discounted 5GB plan being highly attractive and well-supported.

11th Place: y.u mobile

Official Website

https://www.yumobile.jp/

Network Used

Network: NTT Docomo Network
Network Type: MVNO
eSIM Support: Yes
MNP One-Stop Transfer Support: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	1,070
2-3GB	1,070
4-10GB	1,070
11-20GB	2,970
21-30GB	4,170
50GB or more	No Plan

Features

Recommended For: Users needing 5GB to 20GB of data, those wanting U-NEXT bundles, or users with fluctuating data usage
Advantages:
Offers discounted plans bundled with U-NEXT
Unused data can be carried over without expiration
Disadvantages:
As an MVNO, network speeds may be unstable

Available Plans

5GB, 10GB, 20GB

Network Speeds

Lunch Break (12:00-13:00): 66.4Mbps
Regular Hours (14:00-16:00): 72.5Mbps
Commute Hours (17:00-19:00): 40.7Mbps

Call Charges

10-Minute Free Calls: Available
Unlimited Calls: Available
Basic Call Rate: 11 yen/30 seconds with dedicated app, 22 yen/30 seconds without

Detailed Overview

Launched by Y.U-mobile, a joint venture between Yamada Denki and U-NEXT, “y.u mobile” is an MVNO budget SIM using the NTT Docomo network.

y.u mobile offers three plan options: 5GB, 10GB, and 20GB. The 5GB plan is suitable for users needing slightly more than 3GB. The 10GB and 20GB plans include U-NEXT video streaming services, ideal for users interested in video subscriptions.

If data runs low, users can top up with 1GB (330 yen) or 10GB (1,200 yen). The 10GB top-up costs only 120 yen per GB, offering great value, and unused data can be carried over without expiration, making it ideal for users with fluctuating monthly data needs.

12th Place: DTI SIM

Official Website

https://dream.jp/mb/sim/

Network Used

Network: NTT Docomo Network
Network Type: MVNO
eSIM Support: Yes
MNP One-Stop Transfer Support: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	1,485
2-3GB	1,650
4-10GB	1,980
11-20GB	No Plan
21-30GB	No Plan
50GB or more	No Plan

Features

Recommended For: Users with frequent calls and low data usage
Advantages:
As an MVNO, it offers good network speeds across all time periods
All plans include 10-minute free calls
Disadvantages:
No high-capacity plans
Overall pricing is relatively high

Available Plans

2GB, 4GB, 8GB, 16GB, Daily 1.4GB

Network Speeds

Lunch Break (12:00-13:00): 123.7Mbps
Regular Hours (14:00-16:00): 52.3Mbps
Commute Hours (17:00-19:00): 139.7Mbps

Call Charges

10-Minute Free Calls: Included in plans
Basic Call Rate: 22 yen/30 seconds

Detailed Overview

Launched by Dream Train Internet, “DTI SIM” is an MVNO budget SIM using the NTT Docomo network.

DTI SIM offers plans from 2GB to 16GB, plus a daily 1.4GB limit plan. All plans include 10-minute free calls, a major advantage. However, the lack of high-capacity plans and relatively high prices make it less suitable for users needing large data volumes or seeking cost savings.

While DTI SIM uses part of the NTT Docomo network, speeds may drop significantly during congestion. However, for users with high call needs, the included 10-minute free call plans are worth considering.

13th Place: IIJmio

Official Website

https://www.iijmio.jp/

Network Used

Network: Docomo Line / au Line
Network Type: MVNO
eSIM Support: Yes
MNP: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	850
2-3GB	950
4-10GB	950
11-20GB	2,000
21-30GB	2,400
50GB or more	3,900

Available Plans

2GB, 5GB, 10GB, 15GB, 25GB, 35GB, 45GB, 55GB

Network Speeds

Lunch Break (12:00-13:00):
Docomo Line: 3.5Mbps
au Line: 1.7Mbps
Regular Hours (14:00-16:00):
Docomo Line: 212.5Mbps
au Line: 131.6Mbps
Evening Rush (17:00-19:00):
Docomo Line: 142.9Mbps
au Line: 183.5Mbps

Call Charges

Free Call Plans: 5 minutes / 10 minutes / Unlimited Calls
Standard Call Rate: 11 yen/30 seconds (8.8 yen after family discount)

Detailed Overview

IIJmio uses Docomo and au lines, being one of the first budget SIM providers in Japan to support eSIM, making it highly suitable as a secondary SIM.

Starting in March 2025, some plans have been upgraded with increased data and reduced prices, now offering eight tiers from 2GB to 55GB. Pricing is competitive, with the 5GB/990 yen plan standing out for its market value.

IIJmio’s speeds drop significantly during lunch peak hours, with speeds only sufficient for basic social media use during this time.

IIJmio offers a relatively wide range of contract phones, including popular models like “AQUOS sense9” and “Xiaomi 15 ultra” with discounted bundles. If you’re interested in one of these phones, a contract plan could be a good choice.

14th Place: BIGLOBE Mobile

Official Website

https://join.biglobe.ne.jp/mobile/

Network Used

Network: Docomo Line / au Line
Network Type: MVNO
eSIM Support: Yes
MNP: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	1,078
2-3GB	1,320
4-10GB	1,870
11-20GB	5,720
21-30GB	8,195
50GB or more	No Plan

Suitable Scenarios

Music/Radio Focus: Data-free feature significantly saves data.
Backup SIM: Low-capacity plans with data-free options reduce costs.

Available Plans

1GB, 3GB, 6GB, 12GB, 20GB, 30GB

Network Speeds

Lunch Break (12:00-13:00):
Docomo Line: 10.9Mbps
au Line: 19.6Mbps
Regular Hours (14:00-16:00):
Docomo Line: 23.9Mbps
au Line: 28.8Mbps
Evening Rush (17:00-19:00):
Docomo Line: 27.6Mbps
au Line: 22.7Mbps

Call Charges

Free Plans: 3-minute free calls / 10-minute free calls
Call Rates: 9.9 yen/30 seconds (with BIGLOBE call app), 22 yen/30 seconds (standard calls)

Detailed Overview

Operated by the well-known Japanese internet provider BIGLOBE, “BIGLOBE Mobile” is an MVNO using Docomo and au lines, featuring an “Entertainment Data-Free Option” that excludes data usage for services like YouTube.

The provider offers a range of plans from 1GB to 30GB, with diverse data options. However, plan prices are generally high, with the 20GB plan costing 5,720 yen/month. Adding the 308 yen/month “Entertainment Data-Free” option exempts data usage for apps like YouTube and Apple Music.

A downside is its subpar speed performance. Tests show that neither Docomo nor au lines reach the 25Mbps benchmark for smooth HD video streaming during lunch peak hours, making it unsuitable for users seeking an HD video experience.

15th Place: Excite Mobile

Official Website

https://bb.excite.co.jp/exmb/sim/

Network Used

Network: Docomo Line / au Line
Network Type: MVNO
eSIM Support: Yes
MNP: Yes

Pricing

Data Allowance	Monthly Fee (Yen)
1GB or less	690
2-3GB	690
4-10GB	1,430
11-20GB	2,068
21-30GB	4,400
50GB or more	11,198

Features

3GB plan at only 690 yen/month, ideal for light users.
10 plan tiers from 0GB (always speed-limited) to 50GB.
Main SIM savings: Prioritize the 3GB/690 yen plan.
Backup SIM: Always speed-limited (0GB) plan suitable for emergencies.

Available Plans

0GB (speed-limited), 3GB, 7GB, 12GB, 17GB, 20GB, 25GB, 30GB, 40GB, 50GB

Network Speeds

Lunch Break (12:00-13:00):
Docomo Line: 2.8Mbps
au Line: 1.6Mbps
Regular Hours (14:00-16:00):
Docomo Line: 131.9Mbps
au Line: 127Mbps
Evening Rush (17:00-19:00):
Docomo Line: 45.7Mbps
au Line: 47.6Mbps

Call Charges

Call Plans: 3-minute free calls
Standard Call Rate: 11 yen/30 seconds (with Excite call app), 22 yen/30 seconds (standard calls)

Detailed Overview

Operated by the well-known Japanese broadband provider Excite, “Excite Mobile” is an MVNO using Docomo and au lines, offering Fit plans for low-data users and Flat plans for high-data users.

Excite Mobile provides a diverse range of plans from 0GB (always speed-limited) to 50GB. The standout is the 3GB/690 yen plan, one of the lowest-priced budget SIMs available.

Due to reliance on Docomo and au lines, speeds can slow significantly during peak hours. Tests show both lines fall below 5Mbps during lunch hours, causing noticeable lag even for browsing or social media.

The always speed-limited (0GB) plan at 495 yen/month is suitable as a backup SIM but offers little advantage over competitors. This SIM is best for users prioritizing minimal main SIM costs.

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