IIJmio vs Rakuten Mobile: Which Is Cheaper for Foreigners?

IIJmio is cheaper up to about 35GB a month. Rakuten Mobile wins on heavy data, free calls and English support. Prices, residence card sign-up, compared.

· 4 min read · 866 words

Two blank smartphones on a sunny Tokyo desk with a blank card and green tea, split by a blue ribbon

IIJmio is cheaper if you use up to about 35GB a month and rarely make phone calls: its 5GB voice plan is ¥950 against Rakuten Mobile's ¥1,078 for 3GB. Rakuten Mobile gets cheaper once you go past 35GB or call a lot, and it's the one with an English website and multilingual help at some shops.

Last checked: September 28, 2026

Price at your usage

Both carriers publish tax-included prices. IIJmio makes you pick a fixed GB tier each month. Rakuten Mobile has one plan that bills you according to what you actually used.

Monthly data IIJmio (voice SIM) Rakuten Mobile
2GB ¥850 ¥1,078 (up to 3GB)
5GB ¥950 ¥2,178 (3GB to 20GB)
10GB ¥1,400 ¥2,178
15GB ¥1,600 ¥2,178
25GB ¥2,000 ¥3,278 (unlimited)
35GB ¥2,400 ¥3,278
45GB ¥3,300 ¥3,278
55GB ¥3,900 ¥3,278

So at 20GB, IIJmio's 25GB plan costs ¥2,000 and Rakuten costs ¥2,178. At 45GB they're almost level. Beyond that, Rakuten's ¥3,278 has no cap, while IIJmio tops out at 55GB and charges ¥220 per extra 1GB.

IIJmio lets unused data roll over into the next month, which helps if your usage jumps around. Rakuten doesn't need a rollover, because a quiet month drops you to the ¥1,078 tier automatically.

Two things narrow the gap in Rakuten's favour. Calls through the Rakuten Link app are free inside Japan (a few number types are excluded), while IIJmio charges ¥11 per 30 seconds. An hour of calls a month is ¥1,320 on IIJmio. And if you bring a second person, Rakuten takes ¥110 off each line with its family discount, while IIJmio takes ¥100 off each voice line once you have two or more.

See the Rakuten Mobile referral offer

English support

This is where the two are furthest apart for most foreigners.

Rakuten Mobile has an English version of its site, including the plan page and the online application guide. It says some of its shops offer multilingual support. Phone support is Japanese only, and the English pages carry a note that the Japanese text takes priority if the two differ.

IIJmio's sign-up flow, price sheet and help pages are in Japanese. When I searched IIJmio's Q&A site for 英語 (English), it returned no results. If you can read Japanese or are happy using a browser translator, it's manageable. If you can't, expect to struggle when something goes wrong.

Signing up with a residence card

Both accept a residence card (在留カード) for online identity checks.

Rakuten Mobile's document page says the card must be in date, have your address on it, and match the name, address and date of birth on your application. The online check reads the card's IC chip, and if the address on the chip isn't up to date, Rakuten tells you to apply at a shop instead. The only passport on its list is a Japanese one.

IIJmio's application page lists the residence card alongside My Number Card and driver's licence, and says you need a smartphone that can read the card's IC chip. Payment has to be a credit card in the account holder's name. That last point trips up a lot of people who are new to Japan and don't have a Japanese card yet. Rakuten also accepts debit cards and bank transfer as payment methods.

Fees and leaving

IIJmio charges a ¥3,300 initial fee, which it's halving for eSIM applications until November 4, 2026, plus a small SIM issuance fee. It has no cancellation fee and no fee to port your number out. Its minimum term only runs to the end of the month you start.

Going home for the holidays? Rakuten Mobile includes 2GB a month of data roaming in over 100 countries, counted towards your normal plan usage. IIJmio's price sheet says data doesn't work while roaming abroad.

Who should pick which

Pick IIJmio if you read Japanese, have a Japanese credit card, use under 35GB a month and mostly message rather than call. It's the cheaper bill in that case, usually by several hundred yen a month and sometimes by more than ¥1,000.

Pick Rakuten Mobile if you want an English site and shop help, make regular calls, use heavy data, or travel home often. If you're switching an existing number, applying through my referral link gets you 14,000 Rakuten points for an MNP transfer, or 13,000 for a new number.

Rakuten isn't the right pick if you're a light user who never calls. You'd be paying ¥128 to ¥1,228 more each month than IIJmio for things you don't use. If speed at busy times matters to you, I compared IIJmio with ahamo and povo in this speed comparison, and you can check your own numbers in the plan finder.

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