Wikipedia
Iga-ryū
is a historical school of ninjutsu, according to Japanese legend. It became one of the two most well-known ninja schools in Japan, along with the Kōga-ryū. The Iga-ryū originated in the Iga Province in the area around the towns of Iga and Ueno (modern Iga City in Mie Prefecture). Iga-mono is a synonym for Iga ninja.