The Battle of Idano was a battle during the Sengoku period (16th century) of Japan. Seven days after the murder of Matsudaira leader Kiyoyasu (grandfather of Tokugawa Ieyasu) at the hands of the rebel commander Abe Masatoyo, the forces of Matsudaira set out to take revenge against the rebel Masatoyo and his army, and were victorious.