SoftBank Phone Plans in Japan: A Complete Guide

SoftBank is one of Japan's major mobile carriers, sitting right alongside docomo and au at the top of the market.

Even though budget-friendly providers (MVNOs) are becoming more common, SoftBank remains a go-to choice for millions of people in Japan.

In this guide, we will break down the most popular SoftBank phone plans, pricing, and features so you can see exactly what they offer.

Note: If you are an international resident looking for international calling, SMS, or English support, make sure to check the section on "International Calling, SMS, and Roaming Data Fees" later in this article.

Let's get started.

Looking for an Affordable Phone Plan with English Support in Japan?

Sakura Mobile is the top choice for international residents living in Japan.

• Popular 5 GB and 30 GB plans starting at 2,980 JPY/month (tax excluded)
• docomo's fast, reliable 4G LTE/5G network
• Full English support 7 days a week
• Online ordering and next-day shipping
• Over 4.5+★ on Google and Trustpilot

How SoftBank Phone Plans and Fees Work

Before we get into the details of SoftBank's phone and SIM plans, let's quickly look at how their rates work.

When you sign up, there are usually two types of costs: an initial fee and your monthly service fees.

It is much easier to compare plans once you understand this basic structure. Here is a breakdown of these costs.

Unlimited Plans

Mini Fit Plan Plus

Here are the details for each fee, including tax.

The Basic Fee: Data and Voice

Your basic fee is a fixed monthly cost determined by the plan you choose.

Simply put, this covers your voice line and data connection.

SoftBank uses a tiered payment system, meaning your monthly cost changes based on how much data you use.

For example, SoftBank's Merihari Unlimited + plan costs 5,775 JPY (tax included) if you use 2 GB or less in a month. However, if you use more than 2 GB, the fee jumps to 7,425 JPY.

Domestic Voice Call Fees

The voice call fee depends on how long you talk.

For domestic calls on standard post-paid plans, the rate is 22 JPY per 30 seconds (tax included). SoftBank bills you the following month for the minutes you used.

Note: If you do not make any calls, you will not be charged any additional voice usage fees (though your monthly base plan fee still applies).

This is standard for all Japanese mobile carriers: you pay for the calls you make, but receiving calls is free.

There is no charge for receiving calls in Japan, even if the call comes from another country.

This standard voice call rate applies to most current smartphone base plans (excluding Prepaid/Simple Style plans).

Domestic SMS Fees

This is the charge for sending text messages. In Japan, text messages are almost always referred to as SMS (Short Message Service).

You are charged for every message you send.

The cost depends on the length of the message, but it typically starts at 3.3 JPY per message (up to 70 characters). Longer messages will cost more.

Receiving messages is always free.

Just like the voice call fee, this standard SMS rate applies regardless of which plan you choose.

Here is a quick summary:

When you sign up with SoftBank, your monthly bill is made up of three main parts: the fixed monthly plan fees (voice + data), voice call fees, and SMS fees.

The fixed plan fee depends on your specific subscription. It typicall ranges from 3,278 JPY to 7,425 JPY per month, depending on how much data you use.

Voice and SMS fees are added on top based on your usage. These rates are the same for every plan.

Overview of Optional Monthly Fees

Up until now, we have explained the basic fee, voice call fee, and SMS fee. However, when you sign a contract with SoftBank, there are various options for extra services, such as add-ons and monthly installments, that you add to your monthly fee each month. We'll cover them below.

Useful Service Add-Ons

SoftBank offers a variety of optional service. The most commonly used option is the Flat-rate Option + add-on for unlimited domestic calls (excluding premium numbers such as 0570).

SoftBank offers many add-on services, including Voicemail Plus. Since these premium add-ons are optional, the more you choose, the higher your monthly fee will be.

Device Monthly Installments

SoftBank offers the option to buy a new smartphone along with your SIM card plan.

You can pay for the phone in whole or in installments, with payments added to your monthly bill.

If you decide to pay in installments, you can usually choose between 24 and 48 payments.

SoftBank Mobile Plans: Merihari Unlimited Plus & Mini Fit Plan Plus

SoftBank offers several phone and SIM card plans, but the following four plans allow you to get a Japanese phone number. Below are the details for each.

Source: https://www.softbank.jp/mobile/price_plan/

Note:

• These four plans all offer calling (Japanese phone #), data, and SMS.
• 5G is available for all plans (for compatible phones).

Many people might think the Smartphone Debut Plans (Light and Basic) are super cheap, but there are conditions you have to meet to be eligible.

People switching phones while keeping the same phone number, or creating new contracts for kids aged 5-15, are likely to apply for the Merihari Unlimited or Mini Fit Plan Plus. Below are details of these plans.

Merihari Unlimited Plus (For Heavy Data Users)

Note: Tax is included.

Merihari Unlimited + offers unlimited data. SoftBank markets this plan to people who use their phones heavily.

The basic fee has two tiers. Tier 1 is 5,775 JPY and applies when you use less than 2 GB in a month. If you use more than 2 GB, the price automatically increases to 7,425 JPY total.

Voice call and SMS fees are not included in this base price. They will be added to your bill separately.

Mini Fit Plan Plus (For Light Data Users)

Source: https://www.softbank.jp/mobile/price_plan/data/minifit-plan-plus/

The Mini Fit Plan Plus is best for people who do not use much data.

If you use more than the 3 GB limit, your data speed drops to 128 kbps until the end of the month.

Like Merihari Unlimited, this plan uses a tiered system. Your monthly bill changes based on how much data you use.

Voice calls and SMS fees are not included. You pay for what you use, and these charges are added to your basic bill.

International Calling, SMS, and Roaming Rates

We'll start by explaining what each of the three fees mean.

International calling and roaming rates vary depending on the country.

International SMS rates change based on the number of characters in your message.

This can be a little confusing, so we have provided a simple explanation below.

International Calling Rates

International call fees differ depending on the country. We didn't list them all, but a handful are listed below.

Source: https://www.softbank.jp/mobile/service/global/outgoing/call/international-calls/

To learn about the rates for other countries, please check the SoftBank international calling fees page.

International SMS Rates

Sending international texts costs between 100 JPY and 1,000 JPY per message, depending on the length. The table below lists the rates based on character count.

Source: https://www.softbank.jp/support/faq/view/10776

You can check the countries and carriers you can send SMS to on the SoftBank international SMS service areas page.

International Roaming Costs

International roaming fees happen when you use your SoftBank phone in a country outside of Japan.

For example, if you call a friend in Japan from France or watch a YouTube video without WiFi in Canada, you will be charged extra.

These fees vary based on your location, activity, and phone model.

Since this system is complex, we recommend contacting SoftBank for their specific rates before you travel. You can also check the official rates in English below.

SoftBank Global Roaming Service Areas and Rates

Device Rules: Do You Need to Buy a New Phone?

When looking at SoftBank phone plans online, you will often see phone and plan bundles, but you can sign up for just a SIM card. However, if you choose a SIM-only plan, you must make sure your smartphone is unlocked.

Also, phones bought outside Japan might not work with local network signals. Since SoftBank does not provide a compatibility checker for foreign models, you should verify that your phone supports SoftBank's frequency bands (mainly LTE Bands 1, 3, 8, and 41) by checking your device's official specifications.

SoftBank Internet Speeds and Coverage Quality

SoftBank is one of the three largest mobile carriers in Japan, along with au and docomo. They offer a reliable, high-speed mobile connection.

How fast is their network? According to the latest independent data from Opensignal (October 2025), real-world average speeds are as follows:

• Average Download Speed: 55.7 Mbps
• Average Upload Speed: ~8.4 Mbps

Source: Opensignal Mobile Network Experience

Mobile connections can sometimes be unstable, depending on your location. However, with these speeds, you can comfortably watch YouTube videos or browse the web.

SoftBank covers over 99% of Japan's populated areas (4G LTE). Unless you are deep in the mountains, underground, or in a very remote rural area, you should be connected with no problem.

If you are curious about coverage in a specific location, you can check the map below (Japanese only).

SoftBank Service Area Map

English Support: Can You Get Help in Your Language?

When you are ready to sign up for a SoftBank contract, you can apply online or at a store.

• SoftBank Online Shop (Japanese only)
• SoftBank Shop Search (English)

You can also find a nearby location by searching for "SoftBank" on Google Maps.

• Search for SoftBank stores on Google Maps

The SoftBank online shop is convenient, but the application process is entirely in Japanese. We strongly recommend asking a friend who reads Japanese to help you choose this method.

Important Warning: Failing the Credit Screening Process

Even if you successfully apply for a SoftBank contract, you might not be able to start using their service immediately.

Based on feedback from many international residents in Japan, it is common to fail the carrier's screening process.

SoftBank does not publicly disclose its exact screening criteria. However, you may be rejected if your visa is too short or if you do not have a Japanese credit card.

If you are worried about strict screening or have already been rejected, we recommend checking out Sakura Mobile. We are a phone service designed specifically for international residents, offering flexible plans with no complex screening hurdles.

Sakura Mobile

Sakura Mobile: Convenient & English Support

Need a stress-free phone plan in Japan?

Sakura Mobile keeps you connected with long-term eSIM or SIM cards explicitly made for international residents. You can skip the complex paperwork and strict binding contracts usually found in Japan.

FAQ: SoftBank Phone Plans in Japan

If you are still deciding which mobile carrier to choose, these common questions can help you understand the pros and cons of signing a contract with a major Japanese carrier such as SoftBank.

Still comparing your options?

Check out these helpful guides to find the perfect plan for your stay in Japan.

• Best SIM Cards in Japan: Cell Phone Plans for Long-Term Stays
• ahamo Phone Plans: Full English Guide to Pricing & Features