The first E233-0 series train was introduced in December 2006 for use on the Chūō Line (Rapid), Ōme, and Itsukaichi lines, replacing the aging 201 series trains. The fleet of 688 E233-0 series vehicles (10-car x 42, 6-car x 28, 4-car x 25) was delivered by the end of March 2008; 42 ten-car sets T1-T42, and 15 6+4-car sets H43-H57 were constructed primarily for use on the Chūō Line (but also on through services to the Ōme, Itsukaichi, Hachikō, and Fujikyuko Lines), while ten four-car sets Ao458-Ao467 and 13 six-car sets Ao658-Ao670 were constructed for the Ōme Line and Itsukaichi Line. In March 2008 and April 2015, sets Ao458+Ao658 and Ao459+Ao659 were transferred to the Chūō Line and renumbered H58 and H59 respectively.