Resume : Haō Taikei Ryū Knight tells the story of Adeu, a boy who lives his life by the "Ethos of Chivalry" (a code of conduct similar to the Knightly Virtues). He is on a quest to seek the Earth's Blade, a gigantic sword which is capable of reaching the sky from the ground. Along the way, he meets Paffy, who is a princess, and her two escorts: Sarutobi, a ninja, and Izumi, a priest. Together, they partake on an adventurous journey in which he comes across many villains, mostly composed of thieves and bandits who are after the Ryu mechs, which are far stronger than the normal mechs (henceforth referred to as Solids).