Rakuten Mobile vs ahamo: We Ran Both Lines Side by Side | Unlimited Data or Docomo Reliability?
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.'
提示：以下详细内容目前仅提供英文版，中文版即将上线。
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.
Sign up for either plan
¥1,078–3,278/month (unlimited)
Unlimited data, free calls via Rakuten Link, no lock-in
¥2,970/month (30 GB, 5-min calls included)
Docomo network, free roaming, no admin fees
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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)
优点（让人满意之处）
- 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
缺点（需要注意之处）
- 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
实测记录（我们真的测了）
所有照片均拍摄于我们的家庭实测空间。
| 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 |
常见问题
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.
Related notes
Mobile
6 Months on Rakuten Mobile as Our Main Line: What ¥3,278 Unlimited Really Gets You
4.2Mobile
ahamo Hands-On Review: Docomo's ¥2,970 / 30 GB Online Plan and Its Free Overseas Roaming
4.3Mobile
Using Rakuten Mobile Overseas: How Far Does the Free 2 GB Monthly Roaming Actually Go?
4.1Mobile
Activating a Rakuten Mobile eSIM: Every Step and How Long It Really Takes
4.4
💴 Based on both services paid for and run side by side by our editorial team in 2026.