Quick Answer
NTT DoCoMo is Japan’s largest mobile operator with 91.91 million subscribers and 70% 5G coverage. NTT East is a regional fiber provider serving eastern Japan with the FLET’S Hikari brand and up to 25 Gbps on the new Tokyo service launching March 2026. These are sibling companies under NTT Group serving different needs - mobile vs fixed broadband.
Side-by-Side Comparison
NTT DoCoMo and NTT East are both NTT Group companies. They serve different functions in Japan’s telecom market.
| Feature | NTT DoCoMo | NTT East |
|---|---|---|
| Type | Mobile operator | Regional fiber provider |
| Subscribers | 91.91 million (mobile) | 13 million (fiber) |
| Service Area | Nationwide Japan | Eastern Japan only |
| Technology | 5G, 4G LTE | FTTH (FLET’S Hikari) |
| Max Speed | 4.2 Gbps (5G) | 25 Gbps (Tokyo, March 2026) |
| Standard Fiber | Via FLET’S partnership | 1-10 Gbps FLET’S Hikari |
| Mobile Service | Yes | No |
Test NTT DoCoMo speed | Test NTT East speed
Speed Comparison
NTT East’s fiber broadband is faster than DoCoMo’s mobile network for home use. FLET’S Hikari standard plans deliver 1 Gbps symmetric. The new 25 Gbps service launching in Tokyo in March 2026 will be among the fastest residential connections globally.
NTT DoCoMo’s 5G mobile network reaches 4.2 Gbps peak. Real-world averages are lower, typically 100-300 Mbps on 5G. Mobile cannot match fiber for sustained throughput.
Many Japanese households use both. NTT East fiber for home broadband and NTT DoCoMo for mobile connectivity. DoCoMo customers get discounted FLET’S Hikari bundles.
Run a speed test to check your current broadband and mobile speeds.
Coverage
NTT DoCoMo covers all of Japan with 4G LTE and 70% of the population with 5G. It is the strongest rural mobile network in Japan.
NTT East covers eastern Japan only. The boundary runs roughly through central Honshu. Tokyo, Hokkaido, Tohoku, and Kanto fall within NTT East territory. Western Japan (Osaka, Kyoto, Fukuoka) is served by NTT West.
FLET’S Hikari fiber reaches most urban and suburban addresses in NTT East’s territory. Rural areas may only have slower DSL or VDSL options.
Which Should You Choose?
This is not an either-or decision for most users. NTT DoCoMo provides mobile service. NTT East provides home fiber. Most customers need both.
DoCoMo subscribers should bundle FLET’S Hikari from NTT East for discounted pricing. The DoCoMo Hikari plan uses NTT East’s fiber infrastructure with DoCoMo billing.
If choosing only one, NTT East fiber makes sense for home-based workers who rarely need mobile data. NTT DoCoMo alone suits users who rely on mobile hotspot and do not need a fixed line.
Compare au Hikari as an alternative fiber provider in eastern Japan.
Summary
NTT DoCoMo and NTT East are complementary NTT Group services, not competitors. DoCoMo handles mobile (91.91M subs, 70% 5G). NTT East handles fiber in eastern Japan (13M subs, up to 25 Gbps). Most users benefit from both.
Test your connection at Kencang speed test and see the Japan internet overview for the full market.
Last Updated: March 28, 2026 Data Sources: TCA Japan subscriber data, NTT Group press releases