The Niwa clan (丹羽氏, Niwa-shi) was a Japanese samurai clan of northern Honshū that claimed descent from Emperor Kanmu via Prince (785-80) and (d.1069). The Kodama clan was one of several samurai clans originally located in Musashi Province. A branch of the clan settled in Owari Province, of which a branch resided in Niwa District. It is uncertain when they adopted the "Niwa" surname, but during the Muromachi period were in service of the Shiba clan, who were the shugo of Owari Province. The clan rose to prominence in the Sengoku period. Niwa Nagahide became a senior retainer of Oda Nobunaga and after Nobunaga was assassinated at the Honnō-ji Incident, helped Toyotomi Hideyoshi defeat the forces of Akechi Mitsuhide at the Battle of Yamazaki. He also assisted Hideyoshi at the Battle of Shiz