▁intermediate ▁cars ▁sand wich ed ▁between ▁newly ▁built ▁ 1 0 - 3 0 0 ▁series ▁driving ▁cars . ▁ 3 rd - batch ▁train sets ▁based ▁on ▁the ▁J R ▁East ▁E 2 3 3 - 2 0 0 0 ▁series ▁design ▁were ▁introduced ▁from ▁September ▁ 2 0 1 3 . ▁ ▁Oper ations ▁The ▁ 1 0 - 3 0 0 ▁series ▁and ▁ 1 0 - 3 0 0 R ▁series ▁operate ▁on ▁the ▁To ei ▁Shin ju ku ▁Line ▁between ▁ ▁and ▁, ▁and ▁also ▁on ▁inter - running ▁services ▁over ▁the ▁Ke io ▁Line ▁from ▁Shin ju ku ▁as ▁far ▁as ▁ ▁on ▁the ▁Ke io ▁S ag ami h ara ▁Line . ▁ ▁Form ations ▁, ▁the ▁fleet ▁consists ▁of ▁eight ▁eight - car ▁ 1 0 - 3 0 0 ▁series ▁sets ▁( 1 0 - 3 7 0 ▁to ▁ 1 0 - 4 4 0 ), ▁and ▁ 1 5 ▁ten - car ▁ 1 0 - 3 0 0 ▁series ▁sets ▁( 1 0 - 4 5 0 ▁to ▁ 1 0 - 6 2 0 ), ▁all ▁based ▁at ▁O sh ima ▁Dep ot . ▁▁ 1 0 - 3 0 0 R ▁series ▁ ▁The ▁four ▁eight - car ▁ 1 0 - 3 0 0 R ▁series ▁sets ▁( 1 0 - 3 1 0 ▁to ▁ 1 0 - 3 6 0 ) ▁were ▁formed ▁as ▁shown ▁below ▁with ▁six ▁mot ored ▁( M ) ▁cars ▁and ▁two