For the histories of Urawa , Ōmiya and Yono before the merger , see : On April 1 , 2005 , Saitama absorbed the city of Iwatsuki to its east , which became a new ward , Iwatsuki-ku .
For the histories of Urawa , Ōmiya and Yono before the merger , see Urawa-ku and Saitama , Ōmiya-ku and Saitama and Yono and Saitama , respectively . On April 1 , 2005 , it merged with the city of Iwatsuki to its east , which became a new ward , Iwatsuki-ku .