# Naniwasuji Line

The Naniwasuji Line (なにわ筋線, Naniwasuji-sen) is an underground heavy rail line scheduled to open in spring 2031, which will run north-south through central Osaka, primarily under the avenue Naniwasuji [ja]. It has long been pursued by West Japan Railway Company (JR West) and Nankai Railway in order to connect the JR Yamatoji Line (Kansai Main Line) and Nankai Main Line with Shin-Osaka Station, greatly enhancing both companies' connections to Kansai International Airport and Wakayama Prefecture. As of 18 March 2023, the tracks through the northern terminus at Osaka Station and adjoining underground platforms were opened for the Haruka, Kuroshio, Mahoroba and Rakuraku Yamato limited express services as well as ordinary trains on the Osaka Higashi Line.

## Background

While both JR and Nankai operate trains to Wakayama (via the Hanwa Line and the Nankai Main Line, respectively) and to Kansai Airport (via the Kansai Airport Line and the Nankai Airport Line, respectively), neither route is ideal.
For JR, trains must use the Osaka Loop Line past Tennoji Station, both creating and being affected by delays on that line, and bypassing JR Namba Station in the Namba district, which is Osaka's major commercial center. Additionally, until February 2023, the Haruka and Kuroshio trains from and to Kyoto and Shin-Osaka used the aboveground Umeda Freight Line [ja], bypassing Osaka Station, the busiest station in western Japan, entirely. The connection to the Osaka Loop Line past the new Osaka Station underground platforms involves a single track shared trackage with JR Freight service, as well as a level junction crossing the Osaka Loop Line right before Nishikujō Station.
For Nankai, all trains go direct to its terminal at Namba Station, precluding access to points further north, including Umeda, Osaka, and Shin-Osaka stations.
The first proposals to alleviate the problems for both companies through the construction of a new underground line date back to 1982, with further proposals in 1989 and 2004. The line is intended to run primarily under the north-south thoroughfare Naniwasuji (hence the name), branching at its south end to connect both the Yamatoji Line (Kansai Main Line) terminal at JR Namba, and a Nankai line, with Shin-Osaka via a new underground route through what was then JR Freight's Umeda Freight Terminal. The Umeda portion of this plan was eventually incorporated into Phase II of the Osaka Higashi Line project (extension from Shin-Osaka to the underground platforms of Osaka Station), with provisions in place for eventual construction of the Naniwasuji Line itself.
Ridership on the line from the two companies is expected to reach approximately 240,000 people per day.

### JR West

The issue surrounding Osaka Station for JR was alleviated in fiscal 2022 with the opening of the first section (incorporated into the Osaka Higashi Line project, although construction delays have pushed its opening back four years compared to the rest of Phase II), which terminates at the underground platforms of Osaka Station on a route replacing the aboveground Umeda Freight Line. Without constructing an entirely new line through central Osaka, however, the other problems remain.
JR West is expected to be in charge of the section between Osaka Station and JR Namba Station.

### Nankai Railway

Early plans for Nankai called for moving the Shiomibashi Line (the northern end of the Kōya Line) underground and connecting to the Naniwasuji Line via Shiomibashi Station (thus upgrading and increasing traffic on an otherwise lightly traveled, local route), but the company ultimately rejected this routing in favor of one via a new underground station at Namba.

### Hankyu Railway

Hankyu Railway has also announced tentative plans to build a new underground line connecting the Naniwasuji Line to Jūsō Station and another line from Jūsō to a Shin-Osaka Station of its own. The rail link from Osaka to Juso is called the Naniwasuji Link Line (ja:なにわ筋連絡線, Naniwasuji renraku-sen), and the rail link from Juso to Shin-Osaka is called the Hankyu Shin-Osaka Link Line (ja:阪急新大阪連絡線, Hankyu Shin-Osaka renraku-sen). On 27 December 2022, Yasuo Shimada [ja], president of Hankyu Hanshin Holdings, said in an interview by the Sankei Shimbun that Hankyu would open both of these narrow-gauge lines at the same time as the Naniwasuji Line in 2031.

## History

On 9 July 2019, the railway business was approved by the Ministry of Land, Infrastructure, Transport and Tourism under the railway business act. Construction of the project was approved in February 2020.
In February 2023, track switching work took place between the 11th and the 13th of that month (including the decommissioning of the former Umeda Freight Line). Before then, JR passenger trains used a single-track freight spur from Osaka Station to join the Osaka Loop Line at Nishi-Kujō. Track switching was finished within the allotted timeframe and the Haruka and Kuroshio have since been using the new tracks.
The new underground platforms at Osaka Station opened for service on 18 March 2023.

### Current plans

Current plans are to begin construction once the Osaka Higashi Line opens to Osaka Station, with completion anticipated in spring 2031. Total construction costs, including provisions for the line at Kita-Umeda, are projected to total 330 billion yen.

## Stations

| JR | Nankai | Station | Japanese | Transfers | Location |
| ◯ | ◯ | Ōsaka | 大阪 | JR West: Tōkaidō Main Line JR Kyoto Line JR-A47  JR Kobe Line JR-A47  JR Takarazuka Line JR-G47  Osaka Loop Line JR-O11  Osaka Higashi Line JR-F01  JR Tōzai Line JR-H44 : (Kitashinchi Station) Osaka Metro: Tanimachi Line (T20: Higashi-Umeda Station) Yotsubashi Line (Y11: Nishi-Umeda Station) Midōsuji Line (M16: Umeda Station) Hankyu: Kōbe Line Kyoto Line Takarazuka Line (HK-01: Osaka-umeda Station) Hanshin Main Line (HS 01: Osaka-umeda Station) | Kita-ku (North District) |
| ◯ | ◯ | Nakanoshima | 中之島 | Keihan: Nakanoshima Line | Kita-ku (North District) |
| ◯ | ◯ | Nishi-Hommachi [ja] | 西本町 | Osaka Metro: Chūo Line (C16: Hommachi Station, C15: Awaza Station) Midosuji Line (M18: Hommachi Station) Yotsubashi Line (Y13: Hommachi Station) Sennichimae Line (S13: Awaza Station) | Nishi-ku (West District) |
| ◯ | ｜ | JR Namba | JR難波 | JR West: Kansai Main Line ( Yamatoji Line ( JR-Q17 ) Osaka Metro: Yotsubashi Line (Y15: Namba Station) Midosuji Line (M20: Namba Station) Sennichimae Line (S16: Namba Station) Kintetsu:  A Kintetsu Namba Line (A01: Ōsaka Namba Station) Hanshin: Hanshin Namba Line (HS41: Ōsaka Namba Station) Nankai: Nankai Main Line (NK01: Namba Station) Koya Line (NK01: Namba Station) | Naniwa-ku |
| ｜ | ◯ | Nankai Shin-Namba [ja] | 南海新難波 | JR West: Kansai Main Line ( Yamatoji Line JR-Q17 ) Osaka Metro: Yotsubashi Line (Y15: Namba Station) Midosuji Line (M20: Namba Station) Sennichimae Line (S16: Namba Station) Kintetsu:  A Kintetsu Namba Line (A01: Ōsaka Namba Station) Hanshin: Hanshin Namba Line (HS41: Ōsaka Namba Station) Nankai: Nankai Main Line (NK01: Namba Station) Koya Line (NK01: Namba Station) | Naniwa-ku |
| ○ | ◯ | Shin-Imamiya | 新今宮 | Nankai: Nankai Main Line ( Airport Line) (NK03: Shin-Imamiya Station) Koya Line (NK03: Shin-Imamiya Station) JR West: Osaka Loop Line JR-O19  Kansai Main Line ( Yamatoji Line) JR-Q19  Osaka Metro: Midosuji Line (M22: Dōbutsuen-mae) Sakaisuji Line (K19: Dōbutsuen-mae) Hankai: Hankai Line (HN52: Shin-Imamiya Ekimae) | Nishinari-ku |