Best SIM Cards in Japan for International Students [2026]: Rakuten Mobile vs. ahamo vs. IIJmio

For international students coming to Japan, setting up a smartphone is one of the first things you need to do after arrival. This article compares the top SIM options with students’ specific needs in mind.

■ Common Challenges International Students Face When Choosing a SIM in Japan

・Stay duration is typically fixed at one to two years ・Budget is limited, often relying on part-time income ・International calls to family and friends back home are necessary ・Heavy data usage is needed for school, job hunting, and daily life ・Need to get connected right away upon arrival

━━━━━━━━━━━━━━━━━━━━━━ 🎁 Sign up for Rakuten Mobile here

Get bonus points when you sign up via our referral link! ・MNP (number transfer) → 14,000 points ・New contract → 11,000 points

▶ View campaign details here https://r10.to/hFd3ot ━━━━━━━━━━━━━━━━━━━━━━

■ Comparing Three SIM Options

【Rakuten Mobile】 ・Monthly fee: ¥1,078–¥3,278 (automatically adjusted based on data usage) ・Data: Unlimited domestically (within Rakuten network coverage) ・Calls: Unlimited domestic calls when using the dedicated app ・Foreigner sign-up: Available with Residence Card and credit card ・eSIM: Supported (can activate on the day of arrival) ・Contract lock-in: None

【ahamo (NTT Docomo)】 ・Monthly fee: ¥2,970 (20GB) or ¥4,950 (100GB) ・Calls: Domestic calls under 5 minutes are free ・Foreigner sign-up: Possible, but the process can be somewhat complex ・eSIM: Supported ・Contract lock-in: None

【IIJmio】 ・Monthly fee: From ¥850 ・Data: Choose from plans starting at 2GB ・Calls: Additional option fee required ・eSIM: Supported ・Contract lock-in: None

■ 3 Reasons Rakuten Mobile Is Recommended for International Students

・Reason 1: Use data freely without worrying about limits Students use a lot of data — for research, online classes, social media, and maps. With Rakuten Mobile’s unlimited plan, you will never hit a wall at the end of the month.

・Reason 2: Monthly fees are flexible and scale with your usage Whether it is a busy exam month or a quiet break, your bill adjusts automatically to how much data you actually use — with a clear upper limit so there are no surprises.

・Reason 3: Cancel anytime with no lock-in penalties When your study period ends, you can cancel your plan at any time with no extra fees.

■ Summary

For international students, the top priorities should be data allowance, pricing flexibility, and ease of cancellation. Rakuten Mobile strikes the best balance across all three. You can even complete the application before arriving in Japan and get connected on day one.

━━━━━━━━━━━━━━━━━━━━━━ 🎁 Sign up for Rakuten Mobile here

Get bonus points when you sign up via our referral link! ・MNP (number transfer) → 14,000 points ・New contract → 11,000 points

▶ View campaign details here https://r10.to/hFd3ot ━━━━━━━━━━━━━━━━━━━━━━

※ Information in this article is current as of June 2026.