The story you're referring to is (also known as Tenchi Muyo! War on Geminar ). Here’s a concise summary for someone looking to watch it with Indonesian subtitles ("Sub Indo"):

Kenshi Masaki (the half-brother of Tenchi Masaki from the Tenchi Muyo! series) is suddenly transported to a fantasy world called Geminar . In this world, humans and other races use giant humanoid machines called "Seikishi" (Sacred Mechanized Weapons) for warfare and politics.

Would you like a character list or episode guide next?