Koiwa is a district of Edogawa Ward in the east of Tokyo which is further split into North, (Kitakoiwa), East (Higashikoiwa), West (Nishikoiwa) and South (Minamikoiwa). Koiwa Station on the JR Sobu Line is located in Minamikoiwa. The Edogawa (Edo River) runs to the east of Koiwa separating it from Chiba Prefecture on the opposite bank.
Koiwa is typical of the mixed land usage that characterises Edogawa Ward. You’ll find apartments, offices, warehouses, residential homes and vegetable fields all in close proximity.