Cheap SIM Pricing in Japan: Comparing Major Carriers, Sub-brands, and MVNOs

When moving to Japan for study and work, one of the first tasks you need to handle is subscribing to a telecommunications service to stay in touch and access the Internet. However, the mobile tariff market in Japan is extremely diverse with various models from major carriers, sub-brands, and MVNOs. Choosing an option that is both economical and convenient for payment procedures is a common question for many Vietnamese students and workers.

1. Classification of Telecommunication Service Providers in Japan

To clearly understand the mobile tariff landscape in Japan, we need to distinguish between the three main groups of providers currently on the market:

Major Carriers (MNOs - Mobile Network Operators)

Includes four corporations that own their entire proprietary base station infrastructure: NTT Docomo, au (KDDI), SoftBank, and Rakuten Mobile. This group offers the advantages of strong signal reception and direct customer service at large stores spanning across all prefectures. However, monthly rates are typically high and the registration process requires numerous complicated documents.

Sub-brands

Established by the MNO corporations themselves to serve customers looking to optimize costs while still using the primary network infrastructure. These include ahamo (under Docomo), povo 2.0 and UQ mobile (under au), and LINEMO and Y!mobile (under SoftBank). This group reduces in-store staff and focuses on online sales, making prices more affordable than MNOs. Nevertheless, most of these sub-brands require customers to register online and pay using a credit card issued in Japan.

Virtual Network Operators (MVNOs)

These are telecommunication companies that lease signal infrastructure from the four major carriers to provide services. By optimizing operating costs, MVNOs offer highly competitive rates. HD TELECOM is one of the MVNOs specializing in connectivity solutions exclusively for the Vietnamese community living in Japan.

2. Detailed Price Comparison Table of Carriers in Japan

Below is a summary table of listed prices (tax included) recorded based on data updated in August 2026:

3. 12-Month Usage Cost Calculations for Different User Groups

To better visualize the total amount you need to spend in a year, let's do a budget calculation for 3 common practical scenarios:

Scenario 1: International students needing around 20GB/month

International students frequently commute between dormitories, schools, and part-time jobs, requiring sufficient data for looking up documents, maps, and basic entertainment.

• Using Rakuten Mobile: When using between 3–20GB, the monthly fee is ¥2,178. After 12 months, the total cost is ¥2,178 x 12 = ¥26,136.
• Using ahamo or LINEMO: Register for the 30GB plan at ¥2,970/month. The total 12-month cost is ¥2,970 x 12 = ¥35,640.
• Using HD TELECOM Data SIM: Choose the monthly Data SIM plan starting from ¥1,800/month. The total estimated 12-month cost is only from ¥1,800 x 12 = ¥21,600.

Choosing the Data SIM solution from HD TELECOM helps international students save a considerable amount of money each year while eliminating the worry of needing a Japanese credit card for payment.

Scenario 2: Technical interns needing around 10GB/month

Interns working in factories or farms usually already have WiFi at their accommodations, only needing about 10GB/month when going out.

• Using UQ mobile: The 5GB plan (¥2,948/month) is insufficient. If they have to register for the 35GB plan (¥3,828/month), the total 12-month budget will be ¥3,828 x 12 = ¥45,936.
• Using Y!mobile: The 5GB plan costs ¥3,278/month. The total 12-month budget is ¥3,278 x 12 = ¥39,336.
• Using HD TELECOM 12-Month Prepaid SIM: Opting for the 12-month prepaid SIM solution starting from ¥8,000 by HD TELECOM optimizes costs to the maximum without worrying about monthly bill payments.

Scenario 3: A group of 3 roommates living together

Many students and working professionals choose to share a room to save on living expenses.

• Individual unlimited tariff approach: If each person independently registers for an unlimited SoftBank plan (¥8,008/month), the total group cost for 12 months is ¥8,008 x 3 x 12 = ¥288,288 (dropping to ~¥5,148 x 3 x 12 = ¥185,328 when combining all discounts).
• HD TELECOM Pocket WiFi approach: Register for 1 HD TELECOM Pocket WiFi device starting from ¥4,500/month placed in the room for all 3 people to connect. The total 12-month cost for the whole room is only ¥4,500 x 12 = ¥54,000. Split evenly among 3 people, each person spends only about ¥18,000 for the entire year of network fees.

4. Strengths and Flexible Solutions from HD TELECOM

HD TELECOM provides Internet connection solutions that meet the practical criteria of Vietnamese people in Japan:

• COD payment without a credit card: Sub-brands like ahamo, povo, and LINEMO mostly require online registration via a Japanese credit card. At HD TELECOM, you can choose the COD method (paying cash directly to the delivery staff upon receiving the SIM/WiFi). In addition, bank transfers and convenience store (Combini) payments are also supported.
• Vietnamese language support: All inquiries regarding contracts, APN settings, and user guides are directly supported by a team of Vietnamese specialists via phone and messages.
• Diverse network infrastructure: HD TELECOM offers SIM cards operating on the signal infrastructure of all 4 major carriers in Japan: Docomo, au, SoftBank, and Rakuten. However, customers should note that the website currently only lists SoftBank and Rakuten base plans by default. If you require a SIM running on Docomo or au network infrastructure, please contact support directly for a specific quote.
• No complicated contract bindings: Open tariff plans with no troublesome contract penalty clauses, suitable for both short-term and long-term residents in Japan.

5. Disadvantages of MVNO Carriers to Keep in Mind

To give users an objective perspective before making a decision, HD TELECOM outlines some characteristic disadvantages of the MVNO model:

• Network speeds during peak hours: Since they lease infrastructure from the host network, during times of sudden traffic surges such as lunch breaks (12:00 - 13:00) or evenings (20:00 - 22:00), data speeds of MVNO SIMs may drop slightly compared to the prioritized bandwidth of major MNOs.
• Data-Only plans do not support traditional voice calls: All current SIM and eSIM plans from HD TELECOM are dedicated data-only lines. The SIMs do not come with a phone number for regular telecom voice calls or receiving voice SMS. However, daily communication needs can be easily fulfilled via internet calling apps such as Zalo, LINE, Messenger, or Viber.
• Limited number of physical stores: MVNOs cut down on expensive high-street store networks to focus on lowering prices, so most support is handled through online and phone channels.

6. Frequently Asked Questions (FAQ)

1. Can HD TELECOM SIMs make phone calls using a regular number?

Currently, HD TELECOM SIM and eSIM plans are Data-Only lines, meaning they do not have a phone number to make traditional telecom calls. You can fully use free internet calling apps like Zalo, LINE, and Messenger to communicate as usual.

2. How can I buy a SIM running on Docomo or au infrastructure?

The official HD TELECOM website interface currently only displays SoftBank and Rakuten base plans by default. If you want to use a SIM running on Docomo or au infrastructure, please contact us directly via phone at 03-6789-8553 or email at support@hdtelecom.jp for detailed consultation and pricing.

3. How does the COD SIM delivery payment method work?

When registering for a plan, you choose the COD payment method. The delivery service will bring the SIM or WiFi device right to your home address in Japan. You receive the goods and pay cash to the shipper without needing to provide credit card or bank account information.

4. Can newcomers to Japan without a bank card purchase a SIM?

Absolutely. Thanks to support for COD payment and convenience store payments, newcomers to Japan who haven't had time to make a bank card can still own a SIM to use immediately.

7. HD TELECOM Contact Information

HD TELECOM is a telecommunications service brand belonging to 株式会社ベトナム物産 (Telecommunications Business Registration Number: A-06-22505).

• Office: 〒169-0073 東京都新宿区百人町1-16-18 センチュリービル2F (Near Shin-Okubo Station)
• Phone: 03-6789-8553
• Email: support@hdtelecom.jp

Note: Tariffs and service policies in this article are recorded based on data updated in August 2026 and are subject to change over time. Please refer to the latest information on the official HD TELECOM website or contact the support department for accurate consultation.