Good morning, it’s まさきん.
The other day, a Rakuten Mobile flyer showed up in my mailbox. It had a comparison table lining up the unlimited plans from Docomo, SoftBank, and au against Rakuten Mobile’s pricing. Honestly, the numbers surprised me. For a family plan, the math worked out to more than ¥4,000 cheaper per line, per month. Over a year, depending on how many people are in your family, that adds up to a difference in the hundreds of thousands of yen.
I previously wrote a comparison with online-only plans like ahamo, UQ Mobile, and povo. That article covered the budget-SIM price range, roughly a few GB up to around 20GB a month. This time we’re comparing flagship unlimited-data plans, which puts us in a different league starting around ¥6,000 a month. Even when you’re comparing plans where nobody has to worry about data caps, a gap this large is hard to ignore.
The Basis for This Comparison
These figures come from materials Rakuten Mobile itself put together, as of May 2025, and the amounts for the three competitors are the effective per-line price when the family discount applies to three or more lines. Every carrier’s numbers are based on rates published on their own official sites, so as long as the conditions match, anyone can run the same comparison. If your family is on unlimited plans across the board, think of this gap as something that hits your household budget directly.
The Actual Comparison Table
Here are the numbers straight from the flyer. All prices are tax-included, unlimited-data, per-line monthly rates with the family discount applied.
| Carrier | Plan | Monthly Rate (tax incl.) |
|---|---|---|
| Docomo | Docomo MAX | ¥7,238 |
| SoftBank | Teigaku Unlimited | ¥6,798 |
| au | Unlimited MAX+ 5G/4G | ¥6,578 |
| Rakuten Mobile | Saikyo Plan (Unlimited Data) | ¥3,168 |
Even against au, the cheapest of the three, Rakuten Mobile works out to ¥3,410 less. Against Docomo MAX, the gap widens to ¥4,070. If your whole family is on unlimited plans, this difference goes straight into your household budget. The gap tops ¥3,000 no matter which of the three carriers you compare against, so depending on the combination, that can mean savings of more than ¥40,000 a year.
That said, even without the family discount, Rakuten Mobile uses a tiered structure where you pay just ¥1,078 if you stay under 3GB, so you only pay for what you actually use. This comparison is specifically about unlimited plans, so the table above is the relevant reference point, but I think it’s reassuring that even on a single line, you’re never forced into a pricier plan than you actually need.
Lining everything up like this, it’s clear Rakuten Mobile is in a pretty strong position in the unlimited-plan price race. Looking at base pricing alone, the gap is wide enough that it’s actually harder to come up with a compelling reason to pick one of the big three.
About Rakuten Mobile’s Network
Rakuten Mobile has been steadily expanding its own network coverage, and it’s reached a point where it comfortably covers everyday use. Around my home and my workplace, I haven’t run into any real problems. Even when I’ve traveled somewhere unfamiliar for work or leisure, I don’t recall feeling seriously inconvenienced.
If you’d like more detail on signal coverage, I’ve written up what to check when your signal feels weak, and how to fix it, so take a look at that too.
You can check how much your own lines would change using the rate simulator.
Clicking this opens the Rakuten login page. Once you log in, you’ll see the campaign details.
What This Means for My Family
My household is six people: two adults and four kids. If everyone were on an unlimited plan, that ¥4,000 per-line difference works out to ¥24,000 a month across six lines. Over a year, that’s more than ¥280,000. Keep it up for three years, and the gap tops ¥860,000.
That’s enough to add a little more to the family-trip or kids’-lessons budget. You could put it toward education costs, or just save it. The more lines a household has, the more this price difference stacks up, so I feel like the more lines you’re running, the bigger the payoff from switching.
Of course, depending on a kid’s age, an unlimited plan might not even be necessary in the first place. It seems like a good approach to review usage line by line and switch to Rakuten Mobile starting with whichever lines genuinely need unlimited data. Even doing just that much, the monthly savings add up in a meaningful way.
In our house, since we haven’t had any complaints about signal quality either, we’re happy with a setup built mostly around Rakuten Mobile. The money we save goes toward our family’s dining-out and travel budget.
By the way, if you don’t need unlimited data and a few GB up to around 20GB a month is plenty, there’s also my comparison with ahamo, UQ Mobile, and povo. If you’re looking for a lighter option, check that out too.
Summary
Compared to Docomo MAX, SoftBank’s Teigaku Unlimited, and au’s Unlimited MAX+, Rakuten Mobile’s Saikyo Plan works out to ¥3,000 to over ¥4,000 cheaper a month once the family discount is applied. For a family of six, that’s a gap of over ¥280,000 a year, and over ¥860,000 over three years.
The network has also grown to cover more than enough ground for everyday use. If your family is on unlimited plans, I think it’s well worth considering a switch. The more lines your household has, the bigger the effect.
Switching away from a major carrier might feel like a hassle to some people. But these days, every carrier lets you complete the process entirely online, and switching itself has gotten a lot easier than it used to be. Looking at the numbers side by side, I felt like it’s definitely worth the effort to make a move. A few thousand yen of change in your monthly fixed costs might look small, but I think it actually has a big impact on your household finances.
Carrier rate plans and discount conditions may change going forward. When considering a switch, please make sure to check the latest rates and coverage information on each carrier’s official site before making your decision.
Clicking this opens the Rakuten login page. Once you log in, you’ll see the campaign details.
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If you have concerns about Rakuten Mobile coverage or signal quality, you can consult through the official signal improvement request form .
