The Azusa (Japanese: あずさ) is a limited express service operated by the East Japan Railway Company (JR East), which mainly run between Shinjuku and Matsumoto via the Chūō Main Line and Shinonoi Line.

On the Chūō Main Line, limited express Kaiji also runs between Tokyo / Shinjuku, and Kōfu / Ryūō.

【Chiba - Funabashi - Kinshichō / Tokyo】 - Shinjuku - Tachikawa - Hachiōji - 【Ōtsuki - Enzan - Yamanashishi - Isawa-Onsen】 - Kōfu - (Nirasaki) - Kobuchizawa -【Fujimi】 - Chino - Kami-Suwa - 【Shimo-Suwa】 - Okaya - Shiojiri - Matsumoto - 【Toyoshina - Hotaka - Shinano-Ōmachi - Hakuba - Minami-Otari】 A limited express ticket has to be purchased to board an Azusa train, along with the basic fare ticket.

The extra train operated on the Chūō Main Line between Shinjuku to Nagiso, via Tatsuno.

Shinjuku - Tachikawa - Hachiōji - Kōfu - Chino - Kami-Suwa - Okaya - Tatsuno - Shiojiri - Narai - Kiso-Fukushima - Nagiso From 23 December 2017, new E353 series EMUs were introduced on Super Azusa services.

[6] The premier Super Azusa service commenced on 3 December 1994 with the delivery of the first new E351 series tilting EMUs.