(CNN) A Japanese man has become the first person in the world to hold a master's degree in ninja studies, after completing a graduate course that involved learning basic martial arts and how to stealthily climb mountains. Known for their secrecy and high levels of skill, ninjas were masters of espionage, sabotage, assassination and guerrilla warfare dating back to at least the 14th century . Yet Mitsuhashi said ninjas were also independent farmers, and he moved to the mountainous province of Iga, 220 miles from the Japanese capital Tokyo, to better understand how they lived. "Iga is where Ninja used to live. He also teaches martial arts and ninjutsu -- the art of the ninja -- at his own dojo.

Source: CNN June 30, 2020 07:18 UTC