Indotokusatsu: Jyuken Sentai Gekiranger

Synopsis
Four thousand years ago, in China, a form of Kenpō martial arts called the Beast-Fist style was developed. It was created by a man named Brusa Ee, who built the hidden Beast Origin Village. Beast-Fist is a martial art in which one mimics the abilities of animals as well as reach spiritual peace. However, dissent grew among the creator's ten students. Three believed that they should use the suffering and hatred harnessed within humans to increase their power, using their power to assume their monstrous forms, the Three Fist Demons.

After Brusa Ee was murdered, the Fist Demons gathered followers to practice an evil form of the Beast-Fist style known as Confrontation Beast-Fist Akugata. The other seven students believed that true strength should come from within, engaging their former friends in a great war, ending the fight with a forbidden technique to seal the Fist Demons' powers at the cost of losing their own human forms in the process, becoming the Seven Fist Sages. Followers of the Fist Sages created the Fierce Beast-Fist Beast Arts school: the Beast-Fist of justice whose sport discipline enhances the human body with the self-produced positive Qi called "Fierce Ki." It is taught by Grand Master Sha-Fu, one of the seven Fist Sages, using a sports goods company named "SCRTC" as a front. (Wikipedia)

Official Japanese Websites:
Toei's Gekiranger
TV Asahi's Gekiranger
Super-Sentai.net's Gekiranger

Gekiranger The Series