"Tenchu (天誅) is the title of the popular stealth game series originally developed by Acquire wherein the player assumes the role of a ninja. The title in Japanese literally translates in English as: heaven's punishment, ...
Tenchu is known for its stealth gameplay and the eerie settings of feudal Japan. It was one of the first ninja games to incorporate stealth, a very crucial aspect of Ninjutsu. However, aside from featuring traditional martial arts in battles, the game incorporates elements of fantasy and Japanese mythology.
Source: Wikipedia, "Tenchu", available under the CC-BY-SA License.