The was an electric multiple unit (EMU) train type operated by the private railway operator Tokyu Corporation on the Tokyu Ikegami and Tokyu Tamagawa lines in Japan from 1987 to 2018.
The 7700 series originate from the built from 1962-1966.
The 7000 series was Japan's first stainless steel-bodied subway train: these cars were built by Tokyu Car Corporation in partnership with the American Budd Company - the design was based on the SEPTA M-3 trains Budd built for Philadelphia in 1960, but modified for local conditions in Tokyo. These trains served the TÃ Âyoko Line and the Hibiya Line until the 1980s: the stainless steel bodies generally outlasted the bogies and the motors, leading to the decision to combine the bodies with modern equipment such as air conditioning, variable-frequency motor drives and new bogies to form the new 7700 series from 1987 to 1990.
The trains were formed as three-car sets and used on the Tokyu Ikegami Line and Tokyu Tamagawa Line.
The fleet consisted of 15 three-car sets, formed as follows, with two motored ("M") cars and one non-powered trailer ("T") car, and car 1 at the Gotanda/Tamagawa end.
Cars 2 and 3 were each fitted with one lozenge-type pantograph.
Passenger accommodation consisted of longitudinal seating throughout, with a mixture of brown and orange seat moquette.
The 7700 series trains sets were initially formed as two- and four-car sets; however, the fleet was subsequently reformed into three-car sets. Set 7915 was formed in 1996 from three former intermediate cars, and had newly-added cab ends of the same design as the Tokyu 1000 series and Tokyu 9000 series trains. This set was withdrawn in 2010.
Withdrawals commenced in 2000, with six end cars being resold to the Towada Kankà  Electric Railway in Aomori Prefecture. While these three two-car sets retained the "7700 series" classification, they were renumbered 7701+7901 to 7703+7903, irrespective of their original car numbers. The 7700 series sets were completely retired on 24 November 2018.
On 21 August 2018, the Yà Ârà  Railway announced its plans to procure fifteen 7700 series cars to replace nearly half of its 31-vehicle fleet, forming three 3-car sets and three 2-car sets. As part of their transfer, the trains received fareboxes and additional wheelchair spaces, as well as transverse seating bays in the intermediate cars of some 3-car sets. They carry running numbers between TQ01 and TQ14, based on the cars' original numbers.
The Yà Ârà  Railway originally intended to introduce the trains into service in February 2019; however, their introduction was deferred to 27 April 2019, coinciding with the 100th anniversary of the line's completion.
The cab end of former car DeHa 7702 is preserved inside the Maruzen Ikebukuro bookshop in Toshima, Tokyo. Built in March 1966 as 7000 series car DeHa 7046, it was withdrawn in December 2015, and moved to the ground floor of the Maruzen Ikebukuro bookshop building in March 2017, while still under construction.