Niwa clan
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 Shizugatake, and was rewarded with the provinces of Wakasa and Echizen and two districts of Kaga Province, for a total "kokudaka" of 1,230,000 "koku", making him one of the most powerful Sengoku-"daimyō". However, after Niwa Nagahide died in 1585, the clan's fortunes under Niwa Nagashige fell with equal rapidity. During the Siege of Toyama against the forces of Sassa Narimasa, Hideyoshi accused the Niwa clan with collaboration, and seized most of their territories, leaving the clan with only Wakasa Province at 150,000 "koku". During the subsequent Kyūshū Campaign in 1589, one of the Niwa clan retainers was again accused of collaboration with the enemy, and the clan was reduced further to a small 40,000 "koku" holding around Komatsu in Kaga Province. However, Toyotomi Hideyoshi was mercurial in his moods, and in response to Niwa Nagashige's efforts at the Siege of Odawara, his status was brought back to 120,000 "koku".