Big Three Carriers vs. MVNO Sub-Brands

Choosing a Japan mobile carrier means choosing among three system tiers: the big three network owners, their online sub-brands, and leased capacity MVNOs plus fourth carrier Rakuten Mobile.¹ The price bands overlap less than ads suggest, and the right fit follows data use and support need rather than brand alone.²³

Confirm current details with official sources

Procedures, fees, and requirements can change. Confirm current details at the NTT docomo, KDDI au, SoftBank, ahamo, povo, LINEMO, and Rakuten Mobile official plan pages.

Overview

Japan has four network owning carriers: NTT docomo, KDDI au, SoftBank, and Rakuten Mobile.¹ The first three are the long established big three. Rakuten Mobile launched its own network in April 2020 and operates as a fourth carrier rather than a strict MVNO.¹

Online sub-brands sit in the middle. ahamo is owned by docomo, povo by KDDI au, and LINEMO by SoftBank.⁴⁵⁶ They use the parent network with generally identical coverage and speed, but signup and support run online only.¹

MVNOs, or 格安SIM (kakuyasu shimu, "budget SIM"), lease radio capacity from an MNO and resell simpler plans.¹ IIJmio, mineo, BIGLOBE Mobile, and OCN Mobile are named market examples in this tier. Exact BIGLOBE and OCN current fees are not listed here.

Who this guide is for

This guide is for residents choosing a main line on any status of residence.¹ It does not cover short stay travel SIMs. Signup, payment, and language notes stay at concept level; the companion foreign resident procedures article carries the full detail.

The Big Three: docomo, au, SoftBank

The big three are MNO (emuenō, "Mobile Network Operator") carriers that own radio networks and sell through nationwide shops and online stores.¹⁷⁸⁹ They suit users who value in person support, broad coverage, and bundled family or internet discounts.¹²

Coverage is nationwide for all three, but rural and indoor reach differs by carrier and area.¹² docomo is widely described as having the broadest reach. Confirm the contracting carrier area map for home, work, and travel routes before signing.

Premium data plans and typical monthly shape

docomo lists docomo MAX as its 1GB to unlimited entertainment tier alongside mini and points linked tiers.⁷ au lists unlimited tiers including its MAX Plus and value link plans alongside mini plans.⁸ SoftBank lists Peitoku2 and Teigaku Unlimited as its unlimited data shapes.⁹

Unlimited or near unlimited sticker prices sit in roughly the 6K to 10K JPY per month band before discounts (as of 2026-04-28; confirm current figures with each carrier).² SoftBank official base fees anchor that band: Peitoku2 at 10,538 JPY per month and Teigaku Unlimited at 8,008 JPY per month (as of 2026-09-06).⁹

Plan shape	Sticker shape	As of	Notes
Big three unlimited band, secondary comparison	approx. 6K to 10K JPY per month	2026-04-282	Before family and bundle discounts
SoftBank Peitoku2 base fee	10,538 JPY per month	2026-09-069	Unlimited data shape
SoftBank Teigaku Unlimited base fee	8,008 JPY per month	2026-09-069	Unlimited data shape

The table reflects sticker prices before conditions (as of dates shown).⁹² Discounted household prices fall only when family, internet, and card conditions are all met. Solo users without those conditions pay closer to base.⁹

Shop support, device financing, and bundle conditions

Shop support is the main service difference. docomo, au, and SoftBank each keep nationwide physical shops plus online stores.⁷⁸⁹ Sub-brands and most MVNOs do not.

Device financing is separate from plan fees. ahamo states device cost is separate with lump sum or 24 installment choice (as of 2026-09-06).⁴ Rakuten Mobile sells devices with installment and trade in programs.¹⁰ A remaining handset balance survives a plan change or number port.

Discounts stack by household, not by individual. Common conditions are family lines on the same group account, home internet from the same group, and payment with the group card.⁹² SoftBank unlimited examples combine all three: family discount, Hikari set discount, and card payment discount (as of 2026-09-06).⁹

Compare the solo price without family or internet bundles

Ads show the fully discounted household figure. Rebuild the quote with one line, no home internet bundle, and an ordinary card to see the real solo price before signing.⁹

Online Sub-Brands: ahamo, povo, LINEMO

Sub-brands run on the parent MNO radio network, so coverage and speed are generally identical to the main brand.¹ The tradeoff is support: signup, plan changes, and help run online only with no store counter.⁵¹¹⁶ No carrier endorsement follows; each model below fits a different use shape.

ahamo: docomo online-only tier

ahamo is docomo online-only tier on the docomo network.¹² The base plan is 30GB for 2,970 JPY per month tax included, with 5 minute domestic calls free per call and tethering allowed (as of 2026-09-06; confirm current figures with ahamo).⁴¹²

The Oomori option adds 80GB for 1,980 JPY per month, bringing the total to 110GB for 4,950 JPY per month (as of 2026-09-06).⁴¹² Calls beyond 5 minutes cost 22 JPY per 30 seconds, and SMS plus certain connection services cost extra (as of 2026-09-06).⁴

ahamo shape	Monthly fee	As of	Notes
Base 30GB with 5 minute calls	2,970 JPY	2026-09-064	Tethering allowed
Oomori add-on 80GB	1,980 JPY	2026-09-064	Requires base plan
Total 110GB	4,950 JPY	2026-09-064	30GB plus Oomori

Fees above exclude handset cost (as of 2026-09-06).⁴ Signup and transfer carry no administrative handling fee and no shipping fee (as of 2026-09-06).⁴ Support runs through chat or video call rather than docomo shops.¹²

povo: au base plus topping model

povo2.0 starts from a 0 JPY base, with data capacity and call options bought as toppings in the app (as of 2026-09-06).⁵ It uses the au high speed 5G network.⁵

At 0 JPY and 0GB, speed is capped at maximum 128kbps (as of 2026-09-06).⁵ Voice plus data lines pay per use call charges of 22 JPY tax included per 30 seconds plus SMS send charges (as of 2026-09-06).⁵ Data only lines buy an initial topping at signup (as of 2026-09-06).⁵

If no paid topping is bought for over 180 days, the line is sequentially suspended and then cancelled after a further 30 days, with notice by email or SMS.⁵ Irregular users who leave a line idle should set a reminder rather than treating the base as permanent standby.

Idle povo lines need a paid topping every 180 days

The 0 JPY base does not hold forever. One paid topping or qualifying usage inside each 180 day window keeps the line active.⁵

LINEMO: SoftBank online tier

LINEMO is the SoftBank online tier on the SoftBank network.¹¹ Best Plan scales with use: to 3GB at 990 JPY tax included per month and to 10GB at 2,090 JPY tax included per month, with per use domestic calls at 22 JPY per 30 seconds (as of 2026-09-06).⁶

Best Plan V is the heavy tier: 30GB at 2,970 JPY tax included per month with 5 minute domestic calls included (as of 2026-09-06).⁶ LINE talk, voice calls, and video calls do not consume data under LINE Giga Free, with stated exclusions.¹¹⁶

LINEMO shape	Monthly fee	As of	Notes
Best Plan to 3GB	990 JPY	2026-09-066	Per use calls
Best Plan to 10GB	2,090 JPY	2026-09-066	Per use calls
Best Plan V 30GB with 5 minute calls	2,970 JPY	2026-09-066	Heavy tier

Fees above are plan fees before universal service charges (as of 2026-09-06).⁶ LINEMO sells no handsets, accepts online signup only, and offers no family discount.¹¹⁶ New signup, MNP, or number transfer handling costs 3,850 JPY tax included (as of 2026-09-06).⁶

Exceeding the cap throttles speed until month end: Best Plan to 300kbps after 10GB and 128kbps after 15GB, and Best Plan V to 1Mbps after 30GB and 128kbps after 45GB (as of 2026-09-06).⁶

The MVNO Market and Rakuten Mobile

MVNO (emuvienō, "Mobile Virtual Network Operator") carriers lease capacity and resell simpler plans without owning radio infrastructure.¹ Prices run lower, while speeds can slow during midday and evening congestion.¹

How MVNOs work and what 1K to 3K JPY buys

Typical usage plans sit in roughly the 1K to 3K JPY per month band (as of 2026-06-04; confirm current figures with each MVNO).³ IIJmio and mineo official prices anchor that band with concrete rows below.

IIJmio Giga Plan voice SIM at 5GB costs 950 JPY per month tax included, and data eSIM at 2GB on the docomo network costs 440 JPY per month (as of 2026-09-06).¹³ mineo MyPita voice plus data costs 3GB at 1,298 JPY, 7GB at 1,518 JPY, 15GB at 1,958 JPY, 30GB at 2,178 JPY, and 50GB at 2,948 JPY per month (as of 2026-09-06).¹⁴

MVNO example	Monthly fee	As of	Notes
IIJmio Giga Plan voice SIM 5GB	950 JPY	2026-09-0613	Bring your own device, online signup
IIJmio data eSIM 2GB	440 JPY	2026-09-0613	docomo network
mineo MyPita voice plus data 3GB	1,298 JPY	2026-09-0614	Rollover included
mineo MyPita voice plus data 30GB	2,178 JPY	2026-09-0614	Rollover included
mineo MyPita voice plus data 50GB	2,948 JPY	2026-09-0614	Rollover included

The table shows plan fees before initial and universal charges (as of dates shown).¹³¹⁴ mineo lets unused data roll to the next month.¹⁴ IIJmio supports docomo and au network choice plus eSIM.¹³

Match the host network when bringing your current handset

MVNO signup asks for a docomo or au network choice. Check handset band support and SIM lock status before picking the host network.¹³

Rakuten Mobile as fourth carrier

Rakuten Mobile is a fourth MNO with its own network, not a leased capacity MVNO.¹⁵¹ Its single scaling plan is the Rakuten SAIKYO Plan.

The plan scales with use: to 3GB at 1,078 JPY tax included per month (968 JPY with family discount), to 20GB at 2,178 JPY (2,068 JPY with family discount), and over 20GB unlimited at 3,278 JPY (3,168 JPY with family discount) (as of 2026-09-06).¹⁵¹⁰

Rakuten SAIKYO use	Monthly fee	As of	Notes
To 3GB	1,078 JPY	2026-09-0615	968 JPY with family discount
To 20GB	2,178 JPY	2026-09-0615	2,068 JPY with family discount
Over 20GB unlimited	3,278 JPY	2026-09-0615	3,168 JPY with family discount

Fees above are plan fees before handset and handling charges (as of 2026-09-06).¹⁵¹⁰ Domestic calls through the Rakuten Link app are free with no time limit and stated exclusions; standard phone app calls cost 22 JPY per 30 seconds (as of 2026-09-06).¹⁵¹⁰

Overseas roaming includes 2GB per month free across 100 plus countries, counted against plan data, with excess throttled to 128kbps (as of 2026-09-06).¹⁵¹⁰ Points earned from Rakuten payments can be applied to the bill, which is the documented card application bundling pattern for users building a Rakuten payment stack.¹⁵¹⁰

Choosing by Use Pattern

No single tier wins for every resident. The decision follows monthly data, need for shop support, and tolerance for online only procedures.¹² The diagram below maps the three documented patterns without ranking any carrier.

The diagram shows use pattern routing, not a carrier ranking.¹³ Each path below states fit conditions only.

Heavy data use with carrier service need

Main brand plans fit users who want a physical shop, bundled family or internet discounts, and broad coverage handling.¹² Online sub-brands fit heavy users who want carrier network quality with simpler pricing and can accept online only support.¹³

Concrete heavy shapes are ahamo 30GB and Oomori 110GB and LINEMO Best Plan V 30GB on their respective parent networks (as of 2026-09-06; confirm current figures with each carrier).⁴⁶ Rakuten unlimited is the fourth carrier heavy alternative where area coverage checks out (as of 2026-09-06).¹⁰

Moderate use with cost priority

MVNOs fit cost conscious moderate users who can self manage online setup and accept possible peak hour slowdowns.¹³ Rakuten SAIKYO fits moderate to heavy users who want one scaling plan with an unlimited ceiling and app based free calls (as of 2026-09-06).¹⁰

Light routines on home Wi-Fi can use LINEMO 3GB or IIJmio 5GB shapes at the lowest monthly shape (as of 2026-09-06).⁶¹³ Right-size from actual phone settings rather than the advertised maximum.

Foreign resident signup pattern

Standard signup requires identity verification, commonly the residence card showing the current address.¹ Big three and sub-brand contracts commonly expect a Japanese credit card or bank account debit, while some foreigner focused providers accept overseas cards.³

Rakuten Mobile supports full online application with same day eSIM activation and English guidance pages.¹⁵³ Cancellation fees have been prohibited since 2022 and MNP transfer fees were abolished in 2021, so switching itself carries no penalty fee.¹

Good to know

Sticker price vs discounted household price

Advertised discounted figures assume family lines, home internet, and group card payment on one account.⁹ A solo renter with one line and an ordinary card will not clear those conditions. Rebuild the quote at solo terms before comparing sub-brands and MVNOs, where the sticker price is already the solo price.⁹²

MVNO speeds can slow at peak hours

Leased capacity lines can slow when the host network congests, typically around midday and in the evening.¹ Main brands and their sub-brands keep parent network priority. Users on video calls or tethering during those windows should weigh this pattern before choosing on price alone.¹

Device balance can outlast the plan

Handset installments are a separate purchase from the plan fee.⁴ Porting the number or moving to a cheaper tier does not erase the remaining balance. Check the installment end date and trade in terms before any switch, since the device program in this article is descriptive rather than advisory.⁴¹⁰

Coverage maps differ by where you live and travel

All three MNOs cover most populated areas, yet rural roads, mountain areas, and building interiors differ.¹² docomo is widely described as broadest, with au and SoftBank varying by area. Check the contracting carrier map for the actual home address and commute before signing, since this article states the system rather than a universal coverage claim.¹

See also

• Mobile Plan Considerations for Foreign Residents
• Number Portability (MNP) Procedure
• Prepaid SIMs for the First Month
• eSIM and Multi-SIM Setups in Japan
• Internet and TV: Utility Setup Overview
• First Credit Cards in Japan for Foreign Residents

References

Footnotes

1. Zairyu Navi Japan Life Guide. "Japan's Mobile Market Explained: MNO, MVNO and Sub-Brands". Verified April 2026. https://zairyu-navi.com/en/guide/sim/japan-mobile-market-overview ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²² ↩²³ ↩²⁴

2. Living in Japan Guide (ezic). "Best Mobile Carriers in Japan: SoftBank vs AU vs Docomo vs MVNO Compared". Published 2026-04-28. https://japan.x.ezic.info/best-mobile-carriers-japan-softbank-au-docomo-mvno-compared ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹

3. Japan Handbook. "Comparing Mobile Plans in Japan: Save on Phone and Data Bills". Published 2026-06-04. https://japanhandbook.com/comparing-mobile-plans-in-japan-save-on-phone-data-bills/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

4. ahamo (NTT docomo). "料金・データ量". https://ahamo.com/plan/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³

5. povo (KDDI). "povo2.0 Top: 基本料0円, topping model, au network". https://povo.jp/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

6. LINEMO (SoftBank). "料金プラン: LINEMOベストプラン and ベストプランV". https://www.linemo.jp/plan/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴

7. NTT docomo. "料金・割引". https://www.docomo.ne.jp/charge/ ↩ ↩² ↩³

8. KDDI au. "料金・割引 | スマートフォン・携帯電話". https://www.au.com/mobile/charge/ ↩ ↩² ↩³

9. SoftBank. "最新料金プラン一覧". https://www.softbank.jp/mobile/price_plan/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³

10. Rakuten Mobile. "Rakuten最強プラン（料金プラン）". https://network.mobile.rakuten.co.jp/fee/saikyo-plan/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

11. LINEMO (SoftBank). Top page: online-only brand, LINE Giga Free, no device sales, no store signup. https://www.linemo.jp/ ↩ ↩² ↩³ ↩⁴

12. ahamo (NTT docomo). Top page plan summary, 30GB 2,970 JPY and Oomori 110GB 4,950 JPY. https://ahamo.com/ ↩ ↩² ↩³ ↩⁴

13. IIJmio. "ギガプラン". https://www.iijmio.jp/gigaplan/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

14. mineo (OPTAGE). "マイピタ｜料金表". https://mineo.jp/price/mypita/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

15. Rakuten Mobile. Top page: Rakuten SAIKYO Plan tiers and Rakuten Link free domestic calls. https://network.mobile.rakuten.co.jp/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰