Are you preparing for life in Japan for study abroad, a working holiday, a long-term business trip, or employment? One of the first essential tasks you must tackle as soon as you arrive in Japan is setting up your smartphone. In particular, having a Japanese phone number is indispensable for local identity verification, banking, and job hunting for part-time work, which is why many people look up Japan SIM card carrier comparison information.
When choosing a SIM card to use in Japan, there is a key legal requirement you must know first. To open a uSIM that provides a Japanese phone number (capable of voice calls and receiving SMS), you must undergo a Japan Residence Card SIM verification process. You cannot open a SIM card with a phone number using only a short-term tourist passport; you must have a Residence Card (在留カード) with completed foreigner registration.
In this article, we will thoroughly compare the features of Japan's three major mobile networks—SoftBank, NTT docomo, and Rakuten Mobile—and introduce a Japan SIM card recommendation guide tailored perfectly to your lifestyle.
Japan SIM Card Carrier Comparison: Analysis of the 3 Major Networks
Japan's telecommunications environment is similar to Korea's, but there are differences in plan structures and data allowances. You need to accurately understand the characteristics of each network to choose the most economical and convenient SIM card for you.
1. SoftBank Network: High-Capacity Data-Centric
SoftBank boasts a very fast and stable network in Japan, making it particularly popular among young people and heavy data users.
- Data Allowance: Mainly structured around high-capacity plans like 50GB / 100GB
- Calling Options: Pay-as-you-go calling or unlimited calling options available
- Monthly Rates: Around ¥6,480 to ¥8,980 per month (4 plans in total)
- Recommended For: Heavy data users who frequently stream videos, play mobile games, or upload to social media outside the home
2. NTT Docomo Network: Dense Coverage and Diverse Plans
As Japan's largest carrier, Docomo boasts the most stable connectivity not only in urban areas but also in suburbs, underground, and mountainous regions.
- Data Allowance: Highly segmented options from small to medium capacities, such as 1GB / 5GB / 10GB / 20GB / 30GB
- Calling Options: Various choices including 5-minute free calls, 10-minute free calls, or unlimited calls
- Monthly Rates: Around ¥3,480 to ¥9,380 per month (15 plans in total)
- Recommended For: Those with a wide range of daily movement or frequent business trips, or budget-conscious users who want to finely adjust their rates according to actual data usage
3. Rakuten Mobile Network: The Powerhouse of Unlimited Data
Having built its own network relatively recently, Rakuten Mobile is a rapidly growing carrier known for its disruptive unlimited data services.
- Data Allowance: Unlimited data
- Calling Options: Pay-as-you-go calling or 10-minute free calls available
- Monthly Rates: Around ¥6,280 to ¥6,780 per month (2 plans in total)
- Recommended For: Those who want to use the internet limitlessly at home or outside without worrying about data, while avoiding excessively high rates
Japan SIM Card Recommendation Guide by Lifestyle
Everyone uses their smartphone differently. Which carrier suits you best? Here is a matching guide based on typical lifestyles of international students and those on a Japan working holiday SIM.
Type A: "YouTube and Instagram are a must even outside!" Heavy Data Users
- Recommended Carrier: SoftBank (50GB / 100GB plans) or Rakuten Mobile (Unlimited plan)
- Why: If you spend a lot of time outdoors and commuting on public transit, you need plenty of data to stay stress-free. Even if you watch videos daily, choosing SoftBank's high-capacity plans or Rakuten's unlimited plan ensures you can go about your day without worrying about speed throttling.
Type B: "I use Wi-Fi at home and mostly use maps outside!" Budget-Conscious Users
- Recommended Carrier: NTT Docomo (5GB / 10GB / 20GB plans)
- Why: If you have a good Wi-Fi environment at home, school, or work, there's no need to pay for expensive high-capacity plans every month. Choosing Docomo's segmented small-to-medium plans allows you to use Japan's highest-quality Docomo network at reasonable rates in the ¥3,000 to ¥5,000 range, saving you a lot on phone bills.
Type C: "I make a lot of calls and have frequent business contacts!" Business Users & Job Seekers
- Recommended Carrier: NTT Docomo (Plans including 5-minute/10-minute free call options)
- Why: When looking for a part-time job or job hunting in Japan, you will receive many calls from companies or stores, and you will also need to make inquiry calls yourself. Utilizing Docomo's plans with 5-minute or 10-minute free call options is highly advantageous, allowing you to make job-hunting calls reliably without worrying about astronomical phone bills.
Essential Precautions When Opening a Japan Residence Card SIM
When applying for a uSIM with an official phone number in Japan, there are a few unique rules that differ from other countries.
- Residence Card Required (Passports Not Accepted): As mentioned earlier, under Japanese telecommunications law, opening a SIM card with voice call functionality strictly requires a Residence Card with a registered Japanese address. If you have not entered the country yet or have not registered your address, you cannot open a uSIM.
- Check Contract Periods and Cancellation Fees: Many major dealerships and telecom products in Japan impose a mandatory contract period of 12 or 24 months. If you return to your home country or cancel within the contract period, you may face hefty cancellation fees. Therefore, short-term residents or working holiday visa holders with flexible return schedules should safely opt for contract-free products.
- Take Advantage of Prepayment Discounts: If your study abroad or working holiday period is fixed, try using a plan where you prepay for several months at once rather than paying monthly like rent. You can receive significant discounts depending on the duration, which is a great tip for reducing long-term stay costs.
Frequently Asked Questions (FAQ)
Q1. Can I get a SIM card with a phone number directly at the airport as soon as I enter Japan?
No. Most SIM cards sold at airports are tourist data-only SIMs or eSIMs. To open an official uSIM with a phone number, you must first visit the ward office (city hall) and register your Japanese address on the back of your Residence Card to become eligible to apply.
Q2. Are there SIM cards with no cancellation fees even if I cancel early without a contract period?
Yes, there are. All uSIM products handled by KEICALL have no mandatory contract periods, and absolutely no cancellation fees are incurred even if you cancel midway. Therefore, even if your return schedule changes suddenly, you can cancel at any time without any financial loss.
Q3. I want to use an eSIM. Can I apply for one?
You can easily purchase and use an eSIM through KEICALL's partner store, esim-pin.com. However, you must check in advance whether your smartphone model supports eSIM.
Find the Perfect Japan SIM Card for You at KEICALL
Setting up your communication network—the first step of living in Japan—doesn't have to be a headache anymore! At KEICALL, we freely offer a total of 21 diverse uSIM plans from SoftBank, NTT Docomo, and Rakuten Mobile introduced today, all without any contracts.
You can receive exceptional discounts of up to 30% when prepaying for 1 to 24 months to match your stay duration. We also offer unlimited pocket Wi-Fi and home Wi-Fi rental services, which are highly useful during the transition period before your Residence Card is issued. Feel free to consult with us anytime via KakaoTalk, LINE, or Instagram (with support available in Korean), and design the perfect communication product for you on the KEICALL Product Page! In particular, if you want unlimited data and generous capacity, you can check the detailed benefits directly on the KEICALL SoftBank uSIM Plans page.
Tools: Internet Finder