内房線
The first E233-5000 series set, set 501, was delivered from JR East's Niitsu factory on 10 March 2010. In addition to services on the Keiyō Line between Tokyo and , these sets are also used on Sotobō Line through services between Soga and , Uchibō Line through services between Soga and , and on Tōgane Line through services between and .