Masaru Aso was the lab assistant of geneticist Doctor Mochizuki, used as one of his experiments related the creation of the Neo Organism, enabling him to transform into a grasshopper-like being called Kamen Rider ZO. He fled into the mountainside and went into a coma before he was awakened by a telepathic call two years later with an unconscious urge to protect Hiroshi Mochizuki, the son of Doctor Mochizuki.
It's been a long time since the great war between the Three God Generals and the Youkais, an ancient race of monstrous spirits. Since then, imprisoned in a cave protected by the mystical Seal Door, their leader Daimaou and his Youkai army wait, planning for the day they can finally strike. That day has arrived and it is up to the Kakurangers, along with the Three God Generals, to defeat the Youkais, before Daimaou's villainy destroys Earth!
It is the year 1999. The Machine Empire of Baranoia, led by Emperor Bacchus Wrath, has invaded Earth with the intention of wiping out all human life and bringing about machine rule. Chief Counselor Miura of the UAOH (United Airforce Overtech Hardware), in a desperate attempt to quell this invasion, has revived super energies born of the lost civilization of Pangaea. Enlisting an elite squad of the finest officers the UAOH has to offer, Miura has harnessed Tetrahedron Power, granting the team the power to transform into the Ohrangers… and save humanity from its darkest crisis yet!