One of the very first tasks you need to handle right after arriving in Japan for study abroad, a working holiday, or long-term employment is setting up your smartphone. However, due to Japan's complex mobile billing systems, many people end up paying far more than their actual usage warrants. Blindly insisting on "unlimited data" can lead to wasting money on expensive monthly bills, while choosing the wrong calling option can result in unexpected bill shock.
Here is a smart way to cut down on unnecessary fixed expenses by finding a Japan SIM card plan recommendation that perfectly matches your lifestyle. In particular, we will compare Japan SIM data and call options in detail and outline the criteria for choosing the plan that benefits you the most.
Why is Finding the Right Amount of Data and Calls So Important?
While living in Japan, you will find yourself needing to make phone calls more often than you might expect. Whether it is inquiring about rent (yachin), setting up gas and electricity, dealing with ward office (shiyakusho) administrative work, or receiving calls for part-time job interviews, voice calls remain an essential means of communication in Japan.
If you make long phone calls on a basic plan without any calling options, pay-as-you-go call rates will stack up, resulting in unexpected charges on your monthly bill. On the flip side, if you mostly use Wi-Fi at home, school, or the office, there is no need to keep a massive 100GB monthly plan. Therefore, it is crucial to understand your outing frequency, video streaming habits, and monthly calling time beforehand.
Residence Card Required! Essential Knowledge Before Applying for a Japan Phone Number SIM
The first thing you must check for a successful Japan phone number SIM application is your type of identification. To activate an official uSIM that supports voice calls and SMS in Japan, you absolutely need a Japanese Residence Card (在留カード).
You cannot activate a uSIM plan that provides an official phone number using only a passport. If you are a short-term traveler or in a transitional phase where you have not yet received your Residence Card, renting a pocket Wi-Fi—which does not require identity verification—is a safe and convenient alternative. Pocket Wi-Fi can be easily rented without any separate ID verification.
Carrier Data & Call Option Analysis: Which Plan is Right for You?
KEICALL offers a total of 21 diverse uSIM plans utilizing Japan's three major carrier networks. Compare the characteristics of each carrier to find the optimal plan for you.
1. NTT docomo: Detailed Data Customization and Free Call Benefits
If your smartphone usage is relatively consistent and you want to customize your plan based on your calling patterns, we recommend plans using the NTT docomo network. With 15 different plans available, it offers the widest range of choices.
- Data Allowance: Choose from 1GB / 5GB / 10GB / 20GB / 30GB
- Call Options: 5-minute free calls, 10-minute free calls, completely unlimited calls
- Monthly Fee Range: ¥3,480 ~ ¥9,380
- Recommended For: Those who mostly use Wi-Fi and only need data when going out, or those who need short-duration free call options due to frequent calls for part-time job interviews or government offices.
You can check the detailed configuration and pricing of the Docomo SIM plans directly on the KEICALL NTT docomo uSIM Plans Page.
2. SoftBank: Generous Data and Simple Configurations
If you do not have internet at home or are a heavy user who frequently streams videos on YouTube, Netflix, etc., outdoors, the SoftBank network is an excellent alternative.
- Data Allowance: 50GB or 100GB
- Call Options: Pay-as-you-go calls or completely unlimited calls
- Monthly Fee Range: ¥6,480 ~ ¥8,980 (4 plans in total)
- Recommended For: Those who consume a lot of social media images and videos on Instagram, TikTok, etc., and find small data plans insufficient, or those who frequently use smartphone tethering at home without personal Wi-Fi.
3. Rakuten Mobile: Worry-Free Unlimited Data Life
If your monthly data usage fluctuates or you want to use the internet with complete peace of mind, the Rakuten Mobile network plans are a perfect fit.
- Data Allowance: Unlimited data
- Call Options: Pay-as-you-go calls or 10-minute free calls
- Monthly Fee Range: ¥6,280 ~ ¥6,780 (2 plans in total)
- Recommended For: Those who find it tedious to check their monthly data usage, or those who frequently download large files and play mobile games.
Smart Discount Tip to Avoid Wasting Money: Take Advantage of Prepayment Discounts
If you plan to stay in Japan long-term, prepaying for a certain period is much more economical than paying monthly. KEICALL offers a prepayment system where you can pay for uSIM plans in advance, from 1 month up to 24 months all at once.
- Up to 30% Discount: The longer the prepayment period, the higher the discount rate, with an exceptional discount of up to 30% for a 24-month prepayment.
- No Contract & Zero Cancellation Fees: Unlike typical Japanese carriers, you are not locked into a 2-year contract, and there are absolutely no tricky cancellation fees or penalties if you terminate early. You can flexibly cancel at any time to match your schedule, making it highly advantageous for working holiday makers and international students.
Frequently Asked Questions (FAQ)
Q1. I don't have a Residence Card yet. Can I apply for a uSIM in advance?
No. Under Japanese law, activating a uSIM with voice calling capabilities strictly requires physical verification of a government-issued Residence Card. Since activation is impossible with just a passport, you must apply after registering your address at the ward office upon entry and presenting your Residence Card. Until your Residence Card is issued, we recommend renting and using a pocket Wi-Fi, which does not require identity verification.
Q2. Do prepayment discounts apply to uSIM plans as well?
Yes, they do. Just like our Wi-Fi products, all of KEICALL's uSIM plans are eligible for the same discount of up to 30% depending on the prepayment period (1 to 24 months). If your duration of stay is certain, you can save a significant amount on communication costs through prepayment.
Q3. Can I apply for an eSIM?
You can conveniently purchase an eSIM through KEICALL's affiliate partner store, esim-pin.com. However, since many eSIMs are data-only products, those who need a local Japanese phone number (voice calls) are advised to choose an official uSIM product using their Residence Card.
Find the Right Japan SIM Card for You at KEICALL!
Don't stress over complex Japanese carrier contracts anymore. KEICALL offers a variety of pocket/home Wi-Fi rentals and Japanese phone number uSIM plans tailored to your usage patterns, all with no contract and zero cancellation fees. You can receive friendly and fast consultation in Korean via KakaoTalk, LINE, and Instagram, so feel free to contact us anytime. Visit the KEICALL Products Page now to find the perfect plan for you!
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