povo vs IIJmio vs Rakuten Mobile: Best Plan Under 5GB

Under 5GB a month, IIJmio's ¥950 plan is the cheapest steady bill, povo wins if you barely use data, and Rakuten Mobile wins once you make regular calls.

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Three glass jars filled to different low levels on a kitchen shelf, one tied with green string

If you use under 5GB a month, IIJmio's 5GB voice plan at ¥950 is the cheapest steady monthly bill of the three. povo beats it if you use almost no mobile data, because you can keep a povo number for about ¥210 a month. Rakuten Mobile only wins at low data if you also make regular phone calls.

Last checked: September 28, 2026

What each one costs at low usage

The three work differently. IIJmio is a normal monthly plan with fixed GB tiers. Rakuten Mobile has one plan that bills by what you used, starting at ¥1,078 for up to 3GB. povo has a ¥0 base fee, and you buy data "toppings" in the app when you need them. povo toppings run for a set number of days, not calendar months.

Monthly use povo IIJmio (voice SIM) Rakuten Mobile
Almost none 1GB for 180 days, ¥1,260 (about ¥210/month) ¥850 (2GB) ¥1,078
2GB ¥990 (3GB, 30 days) ¥850 (2GB) ¥1,078
3GB ¥990 (3GB, 30 days) ¥950 (5GB) ¥1,078
5GB ¥1,380 (5GB, 30 days) ¥950 (5GB) ¥2,178

All prices include tax. povo also sells 60GB for 365 days at ¥13,200, which it works out as 5GB and ¥1,100 a month. That's cheaper than buying the 5GB topping every 30 days, but you pay for the year up front.

IIJmio lets leftover data roll into the next month. With povo, anything left when a topping expires is gone. When you run out on povo, you drop to a maximum of 128kbps until you buy more.

Calls change the answer

Low data users often still need a phone number for calls: the landlord, the ward office, a clinic. This is where Rakuten comes back in.

  • povo: ¥22 per 30 seconds
  • IIJmio: ¥11 per 30 seconds
  • Rakuten Mobile: free inside Japan through the Rakuten Link app (a few number types are excluded), or ¥22 per 30 seconds from your phone's normal dialler

Take someone using 3GB and making 20 minutes of calls a month. povo comes to ¥1,870, IIJmio to ¥1,390, and Rakuten to ¥1,078. If you call more than that, Rakuten pulls further ahead. If you never call, it's the most expensive of the three at this level.

See the Rakuten Mobile referral offer

povo's catch: the 180-day rule

povo's ¥0 base fee comes with a condition. If you go 180 days without buying a paid topping, povo starts suspending the line, and it cancels the contract 30 days after that if you still haven't bought anything. The exception is if your domestic call and SMS charges in that window go over ¥660. So "¥0 a month" really means "at least one purchase every six months". The cheapest way to do that is the ¥1,260 1GB topping, which lasts 180 days.

That makes povo a good fit for a second SIM, for keeping a Japanese number while you're mostly on Wi-Fi, or for holding on to your number while you're overseas for a few months, as long as you buy a 180-day topping before you go. It's a poor fit if you'd forget to buy a topping and lose the number.

Signing up with a residence card, and eSIM

All three offer eSIM. povo's Calls + Data plan is set up online through the povo app. It accepts a residence card, but the card must have at least 90 days of residence period left, and the application can't go through if the address is shown as undetermined or the back of the card has update history on it. It checks you by reading the card's IC chip and taking a face photo. povo has an English website, but all procedures and support are online only.

IIJmio accepts a residence card too, but it needs a credit card in your own name, and its sign-up pages are in Japanese. Rakuten Mobile accepts a residence card as well and has an English website plus multilingual help at some shops.

Which one I'd pick

If you use a steady 2 to 5GB and rarely call, go with IIJmio. ¥950 for 5GB with rollover is hard to beat.

If you're barely using mobile data, or want a backup number, go with povo, and put a reminder in your calendar for the 180-day rule.

If you make regular calls, or think you might go over 5GB some months, Rakuten Mobile is the safer bill. Its top price is ¥3,278 with no data cap, so a heavy month doesn't catch you out. Signing up through my referral link gets you 14,000 Rakuten points if you bring your number over, or 13,000 for a new one.

Rakuten isn't for you if your usage sits between 3GB and 5GB and you don't call. You'd pay ¥2,178 against IIJmio's ¥950. To compare Rakuten and IIJmio at higher usage, see my IIJmio vs Rakuten Mobile breakdown, or try the plan finder.

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