Japan operates a variety of or or through trains which are direct seamless connections between rail operators, using leased trackage rights and junctions, to cut cross metropolitan area commutes without having to change trains, wait, figure out connections, or cross platforms/stations. Most of these junctions have been constructed well after the lines have been operating. Some far-flung spur lines have been shortened (abandoned stations and track due to low patronage); through service is a frequently used method to integrate the surviving short stub lines into multiple rail operator's systems, enhancing convenience and ridership. Through-service proliferation is increasingly common phenomenon as the railway networks, urban density (and Japan's demographics) have matured and new line construction is minimal.
There are several dozen unique through service runs in Japan, the actual track usage details are complex (but as a seamless service offers an abstraction layer for the end user), the Japanese Wikipedia page has a complete list. Standardization is required for cross railway services, in terms of rolling stock dimensions, rail gauge, overhead power, not to mention coordinated scheduling between a mixture of separate companies and/or government agencies.
Through services in Japan are commonly of two types: unidirectional or bidirectional (unidirectional trains return empty on non-circular tracks). The first usage of through services was on the Tobu Kameido Line in 1904, but was suspended in 1910. Japan's first modern (postwar) through services began in 1960, from the Toei Asakusa Line to Keisei Oshiage Line.
There are also through services that have been discontinued (not listed here).
List of existing services (passenger)
Greater Tokyo Area private railways
Tokyo Metro Hibiya Line : Naka-Meguro Station to Minami-Kurihashi Station (64.6 km) Hibiya Line 20.3 km (Naka-Meguro to Kita-Senju) Tobu Skytree Line 33.9 km (Kita-Senju to Tōbu-Dōbutsu-Kōen as local train) Tōbu Nikkō Line 10.4 km (Tōbu-Dōbutsu-Kōen to Minami-Kurihashi as local train) Tōzai Line : Mitaka Station to Tōyō-Katsutadai Station (56.4 km) JR East Chūō-Sōbu Line 9.4 km (Mitaka to Nakano as local train) Tōzai Line 30.8 km (Nakano to Nishi-Funabashi) Tōyō Rapid Railway Line 16.2 km (Nishi-Funabashi to Tōyō-Katsutadai) Tōzai Line : Mitaka Station to Tsudanuma Station (46.3 km) JR East Chūō-Sōbu Line 9.4 km (Mitaka to Nakano as local train) Tōzai Line 30.8 km (Nakano to Nishi-Funabashi) JR East Chūō-Sōbu Line 6.1 km (Nishi-Funabashi to Tsudanuma as local train) Chiyoda Line : Hakone-Yumoto Station, Hon-Atsugi Station to Kita-Senju Station (Metro Hakone, Metro Sagami and Metro Homeway Romancecar limited express) (104.4 km) Hakone Tozan Line 6.1 km (Hakone-Yumoto to Odawara) Odakyu Odawara Line 79.0 km (Odawara to Yoyogi-Uehara via Hon-Atsugi and Shin-Yurigaoka) Chiyoda Line 19.3 km (Yoyogi-Uehara to Kita-Senju) Chiyoda Line : Hon-Atsugi Station to Kita-Ayase Station (65.9 km) Odakyu Odawara Line 41.9 km (Hon-Atsugi to Yoyogi-Uehara) Chiyoda Line 24.0 km (Yoyogi-Uehara to Kita-Ayase) Chiyoda Line : Hon-Atsugi Station to Toride Station (93.5 km) Odakyu Odawara Line 41.9 km (Hon-Atsugi to Yoyogi-Uehara) Chiyoda Line 21.9 km (Yoyogi-Uehara to Ayase) Jōban Line 29.7 km (Ayase to Toride as local train) Yūrakuchō Line : Shinrinkōen Station to Shin-Kiba Station (68.4 km) Tōbu Tōjō Line 40.1 km (Shinrinkōen to Wakōshi as local train) Yūrakuchō Line 28.3 km (Wakōshi to Shin-Kiba via Kotake-Mukaihara) Yūrakuchō Line : Hannō Station to Shin-Kiba Station (60.3 km) Seibu Ikebukuro Line 37.7 km (Shinrinkōen to Nerima as local train, Semi-Express, Rapid or Rapid Express) Seibu Yūrakuchō Line 2.6 km (Nerima to Kotake-Mukaihara) Yūrakuchō Line 20.0 km (Kotake-Mukaihara to Shin-Kiba) Hanzōmon Line : Chūō-Rinkan Station to Kuki Station (94.9 km) Tōkyū Den-en-toshi Line 31.5 km (Chūō-Rinkan to Shibuya) Hanzōmon Line 16.8 km (Shibuya to Oshiage) Tōbu Skytree Line 39.9 km (Oshiage to Tōbu-Dōbutsu-Kōen as Semi-Express or Express) Tōbu Isesaki Line 6.7 km (Tōbu-Dōbutsu-Kōen to Kuki as Semi-Express or Express) Hanzōmon Line : Chūō-Rinkan Station to Minami-Kurihashi Station (98.6 km) Tōkyū Den-en-toshi Line 31.5 km (Chūō-Rinkan to Shibuya) Hanzōmon Line 16.8 km (Shibuya to Oshiage) Tōbu Skytree Line 39.9 km (Oshiage to Tōbu-Dōbutsu-Kōen as Semi-Express or Express) Tōbu Nikkō Line 10.4 km (Tōbu-Dōbutsu-Kōen to Minami-Kurihashi as Semi-Express or Express) Namboku Line : Ebina Station to Urawa-Misono Station (90.1 km) Sōtetsu Main Line 17.7 km (Ebina to Nishiya) Sōtetsu Shin-yokohama Line 6.3 km (Nishiya to Shin-Yokohama) Tōkyū Shin-yokohama Line 5.8 km (Shin-Yokohama to Hiyoshi) Tōkyū Meguro Line 11.9 km (Hiyoshi to Meguro via Den-en-chōfu) Namboku Line 21.3 km (Meguro to Akabane-Iwabuchi via Shirokane-Takanawa) Saitama Rapid Railway Line 14.6 km (Akabane-Iwabuchi to Urawa-Misono) Namboku Line : Shōnandai Station to Urawa-Misono Station (87.3 km) Sōtetsu Izumino Line 11.3 km (Shōnandai to Futamatagawa) Sōtetsu Main Line 3.6 km (Futamatagawa to Nishiya) Sōtetsu Shin-yokohama Line 6.3 km (Nishiya to Shin-Yokohama) Tōkyū Shin-yokohama Line 5.8 km (Shin-Yokohama to Hiyoshi) Tōkyū Meguro Line 11.9 km (Hiyoshi to Meguro via Den-en-chōfu) Namboku Line 21.3 km (Meguro to Akabane-Iwabuchi via Shirokane-Takanawa) Saitama Rapid Railway Line 14.6 km (Akabane-Iwabuchi to Urawa-Misono) Fukutoshin Line : Shinrinkōen Station to Motomachi-Chūkagai Station (88.6 km) Tōbu Tōjō Line 40.1 km (Shinrinkōen to Wakōshi as local train) Fukutoshin Line 20.2 km (Wakōshi to Shibuya via Kotake-Mukaihara) Tōkyū Tōyoko Line 24.2 km (Shibuya to Yokohama via Den-en-chōfu and Hiyoshi) Minatomirai Line 4.1 km (Yokohama to Motomachi-Chūkagai) Fukutoshin Line : Hannō Station to Motomachi-Chūkagai Station (80.5 km) Seibu Ikebukuro Line 37.7 km (Shinrinkōen to Nerima as local train, Semi-Express, Rapid or Rapid Express) Seibu Yūrakuchō Line 2.6 km (Nerima to Kotake-Mukaihara) Fukutoshin Line 11.9 km (Kotake-Mukaihara to Shibuya) Tōkyū Tōyoko Line 24.2 km (Shibuya to Yokohama via Den-en-chōfu and Hiyoshi) Minatomirai Line 4.1 km (Yokohama to Motomachi-Chūkagai) Tokyo Metropolitan Bureau of Transportation (Toei Subway)
Asakusa Line : Misakiguchi Station, Uraga Station, Zushi·Hayama Station, Haneda Airport Domestic Terminal Station or Nishi-magome Station to Narita Airport Terminal 1 Station(via Keisei Narita Airport Line or Keisei Main Line) or Shibayama-Chiyoda Station (e.g., 85.4 km from Haneda Airport Domestic Terminal to Narita Airport Terminal 1 via Keisei Narita Airport Line) 1.Keikyū Kurihama Line 13.4 km (Misakiguchi to Horinouchi) 2.Keikyū Main Line 4.4 km (Uraga to Horinouchi) —=1. and 2. merged at Horinouchi Station—= 2.Keikyū Main Line 11.4 km (Horinouchi to Kanazawa-hakkei) 3.Keikyū Zushi Line 5.9 km (Zushi·Hayama to Kanazawa-hakkei) —=2. and 3. merged at Kanazawa-hakkei Station—= 2.Keikyū Main Line 32.9 km (Kanazawa-hakkei to Keikyū Kamata) 4.Keikyū Airport Line 6.5 km (Haneda Airport Domestic Terminal to Keikyū Kamata) —=2. and 4. merged at Keikyū Kamata Station—= 2.Keikyū Main Line 9.2 km (Keikyū Kamata to Sengakuji) 5.Toei Asakusa Line 6.9 km (Nishi-magome to Sengakuji) —=2. and 5. merged at Sengakuji Station—= 5.Toei Asakusa Line 11.4 km (Sengakuji to Oshiage) 6.Keisei Oshiage Line 5.7 km (Oshiage to Aoto) —=5. and 6. connected at Oshiage Station—= —=6. and 7. connected at Aoto Station—= 7.Keisei Main Line (from Keisei Ueno Station) 1.2 km (Aoto to Keisei-Takasago) —=8. branched from 7. at Keisei-Takasago Station—= 8.Keisei Narita Airport Line 51.4 km (Keisei-Takasago to Narita Airport Terminal 1)**** 7.Keisei Main Line 48.5 km (Keisei-Takasago to Keisei Narita) —=9. branched from 7. at Keisei Narita Station—= 7.Keisei Main Line 8.1 km (Keisei Narita to Narita Airport Terminal 1) 9.Keisei Higashi-Narita Line 7.1 km (Keisei Narita to Higashi-Narita) —=9. and 10. connected at Higashi-Narita Station—= 10.Shibayama Railway Line 2.2 km (Higashi-Narita to Shibayama-Chiyoda) Mita Line : Ebina Station to Nishi-Takashimadaira Station (67.7 km) Sōtetsu Main Line 17.7 km (Ebina to Nishiya) Sōtetsu Shin-yokohama Line 6.3 km (Nishiya to Shin-Yokohama) Tōkyū Shin-yokohama Line 5.8 km (Shin-Yokohama to Hiyoshi) Tōkyū Meguro Line 11.9 km (Hiyoshi to Meguro via Den-en-chōfu) Toei Mita Line 26.5 km (Meguro to Nishi-Takashimadaira via Shirokane-Takanawa) Mita Line : Shōnandai Station to Nishi-Takashimadaira Station (64.9 km) Sōtetsu Izumino Line 11.3 km (Shōnandai to Futamatagawa) Sōtetsu Main Line 3.6 km (Futamatagawa to Nishiya) Sōtetsu Shin-yokohama Line 6.3 km (Nishiya to Shin-Yokohama) Tōkyū Shin-yokohama Line 5.8 km (Shin-Yokohama to Hiyoshi) Tōkyū Meguro Line 11.9 km (Hiyoshi to Meguro via Den-en-chōfu) Toei Mita Line 26.5 km (Meguro to Nishi-Takashimadaira via Shirokane-Takanawa) Shinjuku Line : Takaosanguchi Station to Motoyawata Station (68.2 km) Keiō Takao Line 8.6 km (Takaosanguchi to Kitano as local train or Express) Keiō Line 32.5 km (Kitano to Sasazuka via Chōfu as local train, Rapid, Semi-Express or Express) Keiō New Line 3.6 km (Sasazuka to Shinjuku) Toei Shinjuku Line 23.5 km (Shinjuku to Motoyawata) Shinjuku Line : Hashimoto Station to Motoyawata Station (61.6 km) Keiō Sagamihara Line 22.6 km (Hashimoto to Chōfu as local train, Rapid, Semi-Express or Express) Keiō Line 11.9 km (Chōfu to Sasazuka as local train, Rapid, Semi-Express or Express) Keiō New Line 3.6 km (Sasazuka to Shinjuku) Toei Shinjuku Line 23.5 km (Shinjuku to Motoyawata) Tobu Railway Nikkō Line : Shinjuku Station to Tōbu-Nikkō Station (Nikkō and Spacia Nikkō limited express) (140.7 km) JR East Yamanote Freight Line 10.0 km (Shinjuku to Tabata) JR East Tōhoku Main Line 50.1 km (Tabata to Kurihashi) Tōbu Nikkō Line 80.6 km (Kurihashi to Tōbu-Nikkō via Shimo-Imaichi) Nikkō Line : Shinjuku Station to Kinugawa-Onsen Station (Kinugawa and Spacia Kinugawa limited express) (146.0 km) JR East Yamanote Freight Line 10.0 km (Shinjuku to Tabata) JR East Tōhoku Main Line 50.1 km (Tabata to Kurihashi) Nikkō Line 73.5 km (Kurihashi to Shimo-Imaichi) Tōbu Kinugawa Line 12.4 km (Shimo-Imaichi to Kinugawa-Onsen) Nikkō Line : Asakusa Station to Aizu-Tajima Station (Section-Rapid or Rapid) (146.0 km) Tōbu Skytree Line 41.0 km (Asakusa to Tōbu-Dōbutsu-Kōen) Tōbu Nikkō Line 87.4 km (Tōbu-Dōbutsu-Kōen to Shimo-Imaichi) Tōbu Kinugawa Line 16.2 km (Shimo-Imaichi to Shin-Fujiwara via Kinugawa-Onsen) Yagan Railway Aizu Kinugawa Line 30.7 km (Shin-Fujiwara to Aizukōgen-Ozeguchi) Aizu Railway Aizu Line 15.4 km (Aizukōgen-Ozeguchi to Aizu-Tajima) Odakyu Electric Railway Odawara Line : Shinjuku Station to Hakone-Yumoto Station (Homeway, Sagami, Hakone and Super Hakone Romancecar limited express) (104.4 km) Odakyu Odawara Line (Shinjuku to Odawara) 82.5 km Hakone Tozan Line 6.1 km (Odawara to Hakone-Yumoto) Odawara Line : Shinjuku Station to Gotemba Station (Asagiri Romancecar limited express) (96.8 km) Odakyu Odawara Line (Shinjuku to Matsuda) 71.8 km JR Central Gotemba Line (Matsuda to Gotemba) 25.0 km Sagami Railway Sōtetsu-JR Direct Line : Ebina Station to Shinjuku Station (57 km) Sōtetsu Main Line (Ebina to Futamata-gawa) Sōtetsu Shin-Yokohama Line (Futamata-gawa to Nishiya) Sōtetsu-JR Direct Line (Nishiya to Musashi-Kosugi) JR Tōkaidō Main Line (Musashi-Kosugi to Ōsaki) JR Yamanote Line (Ōsaki to Shinjuku) Fuji Kyuko Fujikyuko Line : Tōkyō Station to Kawaguchiko Station (114.4 km) JR East Chūō Main Line (Tōkyō to Ōtsuki) 87.8 km Fujikyuko Line (Ōtsuki to Kawaguchiko) 26.6 km
Keihanshin private railways
Osaka Metro Midōsuji Line : Minoh-kayano Station to Nakamozu Station (32.9 km) Kita-Osaka Kyuko Railway Namboku Line (Minoh-kayano to Esaka) 8.4 km Osaka Municipal Subway Midōsuji Line (Esaka to Nakamozu) 24.5 km