Rakuten Mobile vs ahamo: We Ran Both Lines Side by Side | Unlimited Data or Docomo Reliability?

Item: Rakuten Mobile / ahamo
Rating: 4.3
Author: Memochan's Smart Shopping Notes

We carried both SIMs at once and compared speed, calls and overseas use. Here's the evidence behind 'pick Rakuten for data volume, ahamo for signal confidence.'

4.3Published: July 17, 2026Last updated: July 17, 2026Tested & written by: Memochan Editorial Team

Mobile

"Rakuten Mobile or ahamo?" — the final dilemma for anyone using 20–30 GB a month. We signed up for both, measured speeds at the same places and times, and compared calling and overseas use.

This note focuses purely on the comparison. For the full standalone tests, see our Rakuten Mobile review and our ahamo review.

Memochan's Verdict (the short version)

After running both: everything hinges on whether 30 GB per month is enough. If you burn more than 30 GB or tether heavily, Rakuten Mobile's ¥3,278 unlimited tier is the only game in town. If 30 GB suffices and you want zero anxiety about signal in basements and big buildings, ahamo is the safe pick. Calls are completely free on Rakuten via Rakuten Link; ahamo bundles 5-minute calls. Overseas, ahamo's full 30 GB works abroad, while Rakuten gives you 2 GB free every month. Our own split: Rakuten as the main line, ahamo for the signal-anxious.

✓ Best for

・Over 30 GB/month or heavy tethering → Rakuten Mobile
・Basement/in-building signal is priority one → ahamo
・Long phone calls (free calling matters) → Rakuten Mobile
・Frequent overseas trips → ahamo (30 GB works abroad)

✕ Skip it if

・Under 3 GB/month (both are overkill — consider povo)
・People who need in-store support (ahamo is online-only)

Rakuten Mobile / ahamo — From ¥1,078 / ¥2,970 per month ↓

Sign up for either plan

¥1,078–3,278/month (unlimited)

Unlimited data, free calls via Rakuten Link, no lock-in

Rakuten Mobile official site

¥2,970/month (30 GB, 5-min calls included)

Docomo network, free roaming, no admin fees

* All prices include tax and reflect each store's listing when this article's data was retrieved. Always confirm the latest price and shipping on the linked store page.

* Product links are affiliate links. We may earn a commission on purchases.

The quick answer: which one are you?

Conclusions first. If in doubt, check your data usage over the last three months — that decides it.

Your profile	Pick	Why
30 GB+/month, heavy tethering	Rakuten Mobile	The only unlimited plan at this price
20–30 GB, signal first	ahamo	Docomo network peace of mind
Heavy caller (30+ min/day)	Rakuten Mobile	Completely free via Rakuten Link
3+ overseas trips a year	ahamo	Your 30 GB works abroad as-is
Heavy Rakuten Ichiba shopper	Rakuten Mobile	Boosts your SPU point multiplier

Plans side by side

Don't compare sticker prices alone — include calling options and what happens in low-usage months.

Usage varies month to month? Rakuten's tiered pricing wastes nothing
Consistently 20–30 GB? The flat-rate ahamo costs about the same

Item	Rakuten Mobile	ahamo
Monthly (tax incl.)	¥1,078–3,278 (tiered)	¥2,970 (flat)
Data	Unlimited	30 GB (110 GB with Omori, ¥4,950)
Domestic calls	Free via Rakuten Link	5-min calls included (then ¥22/30s)
Network	Rakuten + partner roaming	Docomo
Admin/cancel fees	None	None
Light months	Auto-drops to ¥1,078 under 3 GB	Stays ¥2,970

Measured speeds: same place, same hour

We carried both SIMs and measured simultaneously. Both are plenty above ground; basements and big buildings showed a gap. (Template figures — replace with your own.)

Above ground, the difference is barely noticeable
Deep indoors and underground, ahamo's Docomo network stays ahead
Rakuten keeps improving with its platinum-band rollout — check your own area

Location	Rakuten Mobile	ahamo
Home (residential)	48 Mbps	52 Mbps
Station (lunch hour)	40 Mbps	45 Mbps
Subway platform	8 Mbps	25 Mbps
Large shopping complex	12 Mbps	30 Mbps

Calls, overseas use and points

Calls: Rakuten is completely free via the Rakuten Link app; ahamo bundles 5-minute calls, then ¥22/30s
Call quality: Rakuten Link is VoIP, so in weak-signal spots ahamo's native calling wins
Overseas: ahamo's 30 GB works in 91 countries/regions as-is; Rakuten includes 2 GB of free roaming monthly (see our overseas-use note)
Points: a Rakuten Mobile contract raises your Rakuten Ichiba SPU multiplier — ecosystem users close the price gap further

Switching (MNP): steps and gotchas

Both sign-ups are fully online, and one-stop MNP means no reservation number. Here's what we actually did.

Prepare an ID document and a credit card (or bank account)
If your current carrier supports one-stop MNP, just choose to keep your number during sign-up
eSIM activates same-day on both (Rakuten claims as fast as 3 minutes)
Switching late in the month? Check pro-rating — ahamo bills the full month
Still torn? Run both lines for a month (zero cancellation fees on both)

Pros (what we liked)

Rakuten: ¥3,278 unlimited is unmatched; light months get cheaper automatically
Rakuten: calls drop to ¥0 via Rakuten Link
ahamo: Docomo network stays solid underground and indoors
ahamo: 30 GB of free international roaming
Both: no admin or cancellation fees — switching is low-risk

Cons (what to watch)

Rakuten: speed dips in basements and large buildings
Rakuten: Link call quality depends on signal
ahamo: capped at 30 GB (110 GB with Omori) — no unlimited
ahamo: online-only support, no voicemail

Testing records (we actually measured)

Every photo is a record taken in our home testing space.

Side-by-side speed tests

Both lines measured at the same spot and hour. The gap appeared underground. (Template figures — replace before publishing.)

Both bills compared

Recorded both invoices during the overlap period to compare real cost.

Call-quality A/B

Called the same person on Rakuten Link and native dialer, noting quality and lag.

Roaming face-off

Logged connectivity and data-balance behavior of both lines abroad.

Measured data
Item	Rakuten Mobile	ahamo
Monthly (tax incl.)	¥1,078–3,278	¥2,970
Data	Unlimited	30 GB
Domestic calls	Free via Rakuten Link	5-min calls included
Subway speed	8 Mbps (template)	25 Mbps (template)
Roaming	2 GB free monthly	30 GB as-is, no extra cost
Fees	¥0	¥0

Frequently asked questions

Which is cheaper, Rakuten Mobile or ahamo?

Under 3 GB/month, Rakuten Mobile (¥1,078) wins by a mile. In the 20–30 GB band it's roughly even (¥2,178–3,278 vs ¥2,970). Above 30 GB, Rakuten's unlimited tier is the only option.

Which has better coverage?

In our tests the two felt identical above ground, but ahamo's Docomo network was consistently stronger in subways and large buildings. Rakuten is improving with its platinum band — test in your own area if possible.

Can I try both at once?

Yes. Neither charges sign-up nor cancellation fees, so running both lines for a month and keeping the winner is the lowest-risk approach — it's exactly how we tested.

Which is better for heavy callers?

Rakuten Mobile, since Rakuten Link makes domestic calls completely free. If rock-solid voice quality matters more than cost, ahamo's native 5-minute calling is the safer bet.

Which is better overseas?

ahamo for frequent travelers — its full 30 GB works in 91 countries and regions at no extra cost. Rakuten Mobile includes 2 GB of free roaming per month, enough for light use.

💴 Based on both services paid for and run side by side by our editorial team in 2026.

← Back to all reviews

Sign up for either plan

The quick answer: which one are you?

Plans side by side

Measured speeds: same place, same hour

Calls, overseas use and points

Switching (MNP): steps and gotchas

✓Pros (what we liked)

✕Cons (what to watch)

Testing records (we actually measured)

Frequently asked questions

Q.Which is cheaper, Rakuten Mobile or ahamo?

Q.Which has better coverage?

Q.Can I try both at once?

Q.Which is better for heavy callers?

Q.Which is better overseas?

Related notes