Niwa clan
was a Japanese "daimyō" who served the Oda clan. Nagashige was the eldest son of Niwa Nagahide and married the 5th daughter of Oda Nobunaga. He took part in his first campaign in 1583, assisting his father in the Battle of Shizugatake against Shibata Katsuie. In 1584, the Battle of Nagakute, at the age of thirteen, Nagashige led a troop of the Niwa clan in place of his father, who was ill.