Short answer
A Japan eSIM uses the operators named on the plan page, and that page also shows that plan's network type. Service on the Shinkansen, the Tokyo subway, and in an underground station is the service those operators publish for that place, and their pages say a tunnel or part of a station can still be unusable.
Fact table
As of 2026-10-21
Each claim names its source. The full source list, with the date each page was read, is below.
| Claim | Source |
|---|---|
| On the Japan plan page, the Network line shows that plan's network type, or Network type not specified when the page has none, and the operator names for that plan when it has any. | Wakamo Japan plan page |
| The communications ministry's plan of 25 December 2020 says a Yamagata Shinkansen section's tunnel work finished and mobile service there started on 15 December 2020, completing that year's target of about 1,105 km of tunnels. As of the end of December 2020, the work was finished for every tunnel on Shinkansen sections then open. Tunnels on later extensions were to have mobile service when the extension opened. That tunnel section does not call the work 5G. | Ministry of Internal Affairs and Communications, tunnel plan |
| The ministry's Tohoku bureau says the Hosogoe Tunnel base-station work was finished, and that mobile service on the whole Tohoku and Hokkaido Shinkansen from Tokyo to Shin-Hakodate-Hokuto was scheduled to start on 23 July 2020. The carriers named are NTT docomo, KDDI, and SoftBank. A note says weak spots can interrupt communication, depending on the handset. As of that 9 June 2020 notice, Akita Shinkansen work was still aimed at summer 2020 and Yamagata Shinkansen work at sometime in 2020. The notice does not say 5G. | Ministry of Internal Affairs and Communications, Tohoku Shinkansen |
| The ministry's Shinetsu bureau says the Shiozawa Tunnel and the north section of the Dai-sanzawa Tunnel, between Echigo-Yuzawa and Urasa, were finished on 8 July 2020, and that mobile service in every Joetsu Shinkansen tunnel was to start on 23 July 2020. The carriers named are NTT docomo, KDDI, and SoftBank. The notice also says every Shinkansen tunnel in Niigata and Nagano was to have mobile service. It does not say 5G. | Ministry of Internal Affairs and Communications, Joetsu Shinkansen |
| NTT docomo, with KDDI and SoftBank, says mobile service was scheduled to start on 25 March 2020 in the tunnels between Shin-Aomori and the Aomori entrance of the Seikan Tunnel, and between the Hokkaido entrance of that tunnel and just before Shin-Hakodate-Hokuto, and that this makes mobile service available in the tunnels of the whole Hokkaido Shinkansen. The notice includes Y!mobile. It does not say 5G. | NTT docomo, Hokkaido Shinkansen tunnels |
| The ministry's Kyushu bureau says mobile service was to become available on 30 May 2020 in every tunnel on the Kyushu Shinkansen between Hakata and Kagoshima-Chuo. The carriers named are NTT docomo, KDDI, and SoftBank. The notice does not say 5G, and it does not name the West Kyushu route. | Ministry of Internal Affairs and Communications, Kyushu Shinkansen |
| SoftBank's site carries an e-Access notice, dated 25 April 2014, that from 31 March 2014 LTE is available in the tunnels of the Tokaido Shinkansen between Tokyo Station and Shin-Osaka Station, and that LTE may still be unavailable in some tunnels and in some above-ground sections. The notice does not say 5G. | SoftBank, Tokaido Shinkansen LTE |
| The ministry's Hokuriku page says that after the Kanazawa to Tsuruga opening on 16 March 2024, mobile phones can be used in every Hokuriku Shinkansen tunnel. That page does not name the carriers and does not say 5G. | Ministry of Internal Affairs and Communications, Hokuriku tunnels |
| The ministry's subsidy decision of 1 April 2022 names NTT docomo, KDDI, SoftBank, and Rakuten Mobile as the service providers for the Kanazawa to Tsuruga tunnel work, and says the aim was to finish before the opening so that every Hokuriku Shinkansen tunnel could then have mobile service. | Ministry of Internal Affairs and Communications, Hokuriku subsidy |
| NTT docomo's Tokyo-area subway page, current as of 30 June 2026, is a check of stations where 5G and LTE can be used. The lines listed are Tokyo Metro's Ginza, Marunouchi, Hibiya, Tozai, Chiyoda, Yurakucho, Hanzomon, Namboku, and Fukutoshin lines; Toei's Asakusa, Mita, Shinjuku, and Oedo lines; Yokohama Municipal Subway's Blue and Green lines; and the Minatomirai Line. docomo says some places inside a station may be unusable. | NTT docomo, Tokyo-area subway stations |
| NTT docomo's article of 1 May 2026, noted as of 22 April 2026, says radio from base stations above ground does not reach underground, so stations and tunnels need their own equipment, and that concrete keeps radio from traveling far. It says Tokyo Metro stations already had 3.5 GHz equipment for 4G (LTE), and that docomo is switching that equipment to 5G. It states an aim to provide 5G at more than 60% of Tokyo Metro stations by the end of April 2026, with service starting at a station once that station is ready, on all nine lines. It calls 5G in the tunnel sections the major task still ahead. | NTT docomo, Tokyo Metro station 5G |
| The Tokyo Metropolitan Bureau of Transportation says that at every Toei Subway station, and on trains in every section, a mobile phone can be used for email and for an internet connection. That sentence does not name a carrier. | Tokyo Metropolitan Government, Toei subway phones |
| The same bureau says the signal can be poor depending on the place, and asks you to move. At a station under improvement work, antennas are relocated and the signal can be weaker. A fault can also be specific to the carrier. | Tokyo Metropolitan Government, subway signal |
| Tokyo Metro's release of 18 March 2013, with NTT docomo, KDDI, SoftBank Mobile, and e-Access, says mobile service on every Tokyo Metro line was scheduled to start at noon on 21 March 2013, except the Yurakucho and Fukutoshin section between Kotake-Mukaihara and Senkawa, which was scheduled to finish in fiscal 2016. It says internet and email then work inside stations and on trains between stations, and that service may be unusable during a power failure, among other cases. | Tokyo Metro, mobile service on all lines |
FAQ
Which operators does a Japan eSIM use on the train?
The Japan plan page names the operators for the plan you open, and it shows that plan's network type on the same Network line. When the page has no network type, the line says Network type not specified. This page does not give one operator list for every Japan plan.
Does it work in Shinkansen tunnels?
The communications ministry's plan of 25 December 2020 says the tunnel work was finished, as of the end of December 2020, for every tunnel on Shinkansen sections then open, about 1,105 km, after a Yamagata Shinkansen section started mobile service on 15 December 2020. Separate notices schedule mobile service for 23 July 2020 on the Tohoku and Hokkaido Shinkansen from Tokyo to Shin-Hakodate-Hokuto and in every Joetsu Shinkansen tunnel, for 25 March 2020 in the Hokkaido Shinkansen tunnels docomo names, and for 30 May 2020 in every tunnel between Hakata and Kagoshima-Chuo. An e-Access notice on SoftBank's site says LTE in Tokaido Shinkansen tunnels between Tokyo and Shin-Osaka from 31 March 2014, and that some tunnels and some above-ground sections may still have no LTE. After 16 March 2024, the ministry's Hokuriku page says every Hokuriku Shinkansen tunnel can be used. The tunnel section of the 2020 plan does not call that work 5G.
Is Shinkansen service 5G or LTE?
The Tohoku, Joetsu, Hokkaido, Kyushu, and Hokuriku notices say mobile phone service and do not say 5G. SoftBank's Tokaido notice says LTE, and says LTE may still be unavailable in some tunnels and in some above-ground sections. The network type on the plan page is that plan's own line. It is not a statement that a tunnel is 5G.
Does it work on the Tokyo subway, including between stations?
NTT docomo's station page, current as of 30 June 2026, is where you check 5G and LTE at stations on the nine Tokyo Metro lines, the four Toei lines, Yokohama Municipal Subway's Blue and Green lines, and the Minatomirai Line. docomo says some places inside a station may be unusable. For Toei, the Tokyo Metropolitan Bureau of Transportation says email and internet work at every station and on trains in every section, and that the signal can still be poor in a given place. Tokyo Metro's 18 March 2013 release says internet and email were scheduled from noon on 21 March 2013 inside stations and on trains between stations, on every line except Yurakucho and Fukutoshin between Kotake-Mukaihara and Senkawa. docomo's 1 May 2026 article calls 5G in the tunnel sections the major task still ahead.
Do underground stations get a signal?
NTT docomo says radio from base stations above ground does not reach underground, so a station or a tunnel needs its own equipment, and that some places inside a station may still be unusable. Toei says the signal can be poor depending on the place, and that a station under improvement work can have a weaker signal because the antennas have been moved. A fault can also be limited to one carrier.
Which carriers do the tunnel notices name?
The Tohoku, Joetsu, Hokkaido, and Kyushu notices name NTT docomo, KDDI, and SoftBank. The Hokkaido notice also includes Y!mobile. The Tokaido LTE notice is e-Access. Tokyo Metro's 2013 release names NTT docomo, KDDI, SoftBank Mobile, and e-Access. The April 2022 Hokuriku subsidy names NTT docomo, KDDI, SoftBank, and Rakuten Mobile. The later Hokuriku page, which says the tunnels can be used after 16 March 2024, does not repeat those names. Toei's sentence about every station does not name a carrier. A plan uses the operators named on its own plan page.
Sources
Wakamo Japan plan pagewakamo.io
Wakamo product information. The Network line shows that plan's network type, or Network type not specified when the page has none, and the operator names for that plan when it has any.
Accessed 2026-10-21.
Ministry of Internal Affairs and Communications, tunnel plansoumu.go.jp
ICT Infrastructure Regional Development Master Plan 3.0, 25 December 2020. A Yamagata Shinkansen section's tunnel work finished and mobile service there started on 15 December 2020, which completed the 2020 target of about 1,105 km of tunnels. As of the end of December 2020, that work was finished for every tunnel on Shinkansen sections then open. Later extensions were to have mobile service when they opened. The tunnel section does not call that work 5G.
Accessed 2026-10-21.
Ministry of Internal Affairs and Communications, Tohoku Shinkansensoumu.go.jp
9 June 2020. The Hosogoe Tunnel base-station work was finished, and mobile service on the whole Tohoku and Hokkaido Shinkansen from Tokyo to Shin-Hakodate-Hokuto was scheduled to start on 23 July 2020. NTT docomo, KDDI, and SoftBank. Weak spots can interrupt communication depending on the handset. Akita work was still aimed at summer 2020, and Yamagata work at sometime in 2020. The notice does not say 5G.
Accessed 2026-10-21.
Ministry of Internal Affairs and Communications, Joetsu Shinkansensoumu.go.jp
16 July 2020. The Shiozawa Tunnel and Dai-sanzawa Tunnel (north), between Echigo-Yuzawa and Urasa, were finished on 8 July 2020, and mobile service in every Joetsu Shinkansen tunnel was to start on 23 July 2020. NTT docomo, KDDI, and SoftBank. The same notice says every Shinkansen tunnel in Niigata and Nagano was to have mobile service. It does not say 5G.
Accessed 2026-10-21.
NTT docomo, Hokkaido Shinkansen tunnelsdocomo.ne.jp
11 March 2020, joint with KDDI and SoftBank. Mobile service was scheduled to start on 25 March 2020 in the tunnels between Shin-Aomori and the Aomori entrance of the Seikan Tunnel, and between the Hokkaido entrance and just before Shin-Hakodate-Hokuto. docomo says that makes mobile service available in the tunnels of the whole Hokkaido Shinkansen. Y!mobile is included. The notice does not say 5G.
Accessed 2026-10-21.
Ministry of Internal Affairs and Communications, Kyushu Shinkansensoumu.go.jp
27 May 2020. Mobile service was to become available on 30 May 2020 in every tunnel on the Kyushu Shinkansen between Hakata and Kagoshima-Chuo. NTT docomo, KDDI, and SoftBank. The notice does not say 5G and does not name the West Kyushu route.
Accessed 2026-10-21.
SoftBank, Tokaido Shinkansen LTEsoftbank.jp
An e-Access notice dated 25 April 2014 on SoftBank's site. From 31 March 2014, LTE in the tunnels of the Tokaido Shinkansen between Tokyo Station and Shin-Osaka Station. LTE may still be unavailable in some tunnels and in some above-ground sections. The notice does not say 5G.
Accessed 2026-10-21.
Ministry of Internal Affairs and Communications, Hokuriku tunnelssoumu.go.jp
After the Kanazawa to Tsuruga opening on 16 March 2024, mobile phones can be used in every Hokuriku Shinkansen tunnel. The page does not name the carriers and does not say 5G.
Accessed 2026-10-21.
Ministry of Internal Affairs and Communications, Hokuriku subsidysoumu.go.jp
Subsidy decision of 1 April 2022. Names NTT docomo, KDDI, SoftBank, and Rakuten Mobile as the service providers for the Kanazawa to Tsuruga tunnel work, and says the aim was to finish before opening so every Hokuriku Shinkansen tunnel could then have mobile service. This is the decision, not the later completion page.
Accessed 2026-10-21.
NTT docomo, Tokyo-area subway stationsdocomo.ne.jp
A station check for 5G and LTE, current as of 30 June 2026, for Tokyo Metro, Toei Subway, Yokohama Municipal Subway, and the Minatomirai Line. Some places inside a station may be unusable. The page points to docomo's service-area map for the service area.
Accessed 2026-10-21.
NTT docomo, Tokyo Metro station 5Gdocomo.ne.jp
Article dated 1 May 2026, note as of 22 April 2026. Radio from base stations above ground does not reach underground, so stations and tunnels need their own equipment. Concrete limits how far radio travels. Station equipment that was 4G (LTE) on 3.5 GHz is being switched to 5G. docomo states an aim to provide 5G at more than 60% of Tokyo Metro stations by the end of April 2026, starting station by station on all nine lines. 5G in the tunnel sections is the remaining major task.
Accessed 2026-10-21.
Tokyo Metropolitan Government, Toei subway phoneskotsu.metro.tokyo.jp
At every Toei Subway station, and on trains in every section, a mobile phone can be used for email and for an internet connection. The sentence does not name a carrier and does not say voice calls.
Accessed 2026-10-21.
Tokyo Metropolitan Government, subway signalkotsu.metro.tokyo.jp
Depending on the place, the signal can be poor, and Toei asks you to move. At a station under improvement work, antennas are moved and the signal can be weaker. A fault can also be specific to one carrier.
Accessed 2026-10-21.
Tokyo Metro, mobile service on all linestokyometro.jp
Release of 18 March 2013 by Tokyo Metro, NTT docomo, KDDI, SoftBank Mobile, and e-Access. From noon on 21 March 2013, mobile service on every Tokyo Metro line except Yurakucho and Fukutoshin between Kotake-Mukaihara and Senkawa, which was scheduled to finish in fiscal 2016. Internet and email work inside stations and on trains between stations. It may be unusable during a power failure, among other cases.
Accessed 2026-10-21.