A mecha otaku is reincarnated into another world as Ernesti Echevarria, also known as Eru. In this world, huge humanoid weapons known as Silhouette Knights exist. Dreaming of piloting those robots, Eru and his friends, Archid Olter and Adeltrud Olter, aim to become Knight Runners.
A young genius programmer has a passion for building model robots. After dying in a car accident, he finds himself reincarnated in a world where robots are real, and he can pilot and build them!
A huge behemoth is rampaging through the forest on its way towards the capital, and only Ernesti can stop it. He "borrows" a Silhouette Knight from one of the other students and goes off to face it, but he's so tiny his feet can't even reach the pedals!
After his defeat of the Behemoth, Ernesti goes to the capital to be rewarded. But the king is cautious about this new child who can take down a monster that easily defeats armies, and sets for him a difficult task before his reward can be given.
Ernesti continues his work on the new mech: The Telestale. The new mech has serious design flaws, but even before things can be fully fixed, he's summoned by the Marquis Dixgard, a powerful lord with an interest in the young boy's work. Does he want the glory of designing the new weapon for himself?
The new mechs are to be sent to Fort Casadeus, where the powerful Marquis Dixgard will take personal command over them. But on the way, a group of raiders lure demon beasts into attacking the convoy, hoping to steal them for their own.
With the Casadeus incident resolved, it's time for work on the Telestale to be completed. The nation's biggest mech design lab, the Silhoutte Knight Laboratory, is sent a copy so that they can attempt to make one of their own, and a tournament between the two will be held to see if Ernie's designs are as powerful as they seem.
Ernie's new mech, the Tzendolg, as well as his Telestales, are paired off against the Kaldatoah Darsch, the Lab's new mech. Several Darsch are paired against a single mech, putting the Silver Phoenix at a serious disadvantage before the fight even begins.
A horde of shellcased, powerful demon beasts, are heading for Alfheim, the center of the nation's Silhouette Knight reactor design. If it falls, it will be impossible for any more Silhoutte Knights to be built. But if Ernie can save them, he'll finally get the ability to truly design his own mech from the ground up.
The powerful Jarodek empire is attacking the Occident countries in an attempt to unify their side of the mountains. When things get out of hand, it's a perfect opportunity for Ernie to try out his new mech!
Using special Silhouette Gears, the Order of Silver Phoenix successfully rescue Eleonora, Martina and Isadola. Cristobal sends a party to chase after them, but their pursuers are easily defeated by Eru's Ikaruga and forced to flee.
Ernie repels the Bronze Fang Ambush, but now the Jarodeks know where Eleonora is. Can Ernie hold off their levitate ships?
The Jarodeks launch a counterattack with a powerful flying wyvern mech. Ernie fights back, but his foe this time is far smarter than before, and has a new trap that can defeat even the Ikaruga!
After two draws, it's time for the final showdown against the Vyver! The capital city is almost at hand, and all that remains for the Western Grand STorm to come to a close is for Ernie to defeat the huge wyvern mech.
