The E721 series (E721系) is an AC electric multiple unit (EMU) train type operated by East Japan Railway Company (JR East) on services in the Sendai area of Japan since February 2007.

[3] The two motored cars (KuMoHa and MoHa) each have one PS109 single-arm pantograph.

[2] Two sets, P-1 and P-19, were derailed and badly damaged by the 2011 Tōhoku earthquake and tsunami on 11 March 2011 while at Shinchi Station.

[9] The new trains are built by J-TREC, with construction shared between the company's Yokohama and Niitsu factories.

[9] The first four E721-1000 series intermediate cars were delivered from J-TREC's Niitsu factory to its Yokohama factory in September 2016 to be combined with driving cars built there.

[2] The delivery of E721-500 series cars are as follows:[citation needed] All manufactured by J-TREC.