A mecha otaku is reincarnated into another world as Ernesti Echevalier, also known as Eru. In this world exists a huge humanoid weapons known as Silhouette Knights. Dreaming of piloting those robots, Eru, with childhood friends, Archid and Adeltrud Walter, aim to become Knight Runners, pilots of these Silhouette Knights.

Kurata Tsubasa is not your average citizen. Sure, he's a genius programmer and software engineer, but as far as he's concerned, his most important trait is that he's a hardcore mecha nerd. So, what happens when you take that nerd and reincarnate him into a fantastic world of swords and sorcery? Well, you'd think he'd be disappointed...but this world has magical giant robots! Obviously, Tsubasa—reborn as Ernesti Echevalier—now wants to devote his life entirely to these wondrous pieces of technology. But how exactly can young Ernie achieve his ultimate goal of getting his very own mech? He'll have to rely on his imagination, uninhibited by the common sense of this new world, as well as his extreme dedication and focus! He also might just find help in the form of a rather interesting quirk... (Source: J-Novel Club)

Watt Sears has traded his glory days as a Mechsteel knight for a humble life as train station employee with a knack for showing new pilots the ropes. Problem is, the city's baron—his boss—would love nothing more than to see Watt reclaim his old mantle as a Steelrider who hunts monsters and defends the city. Now nearing forty, the once-legendary pilot would much rather support the new generation than stand in the spotlight himself. Peace and quiet were the last things waiting for Watt, however, as his storied past literally comes to find him. When Anna, his long-lost daughter from a bygone romance, appears before him to ask for his help in a brewing royal power struggle, Watt vows to protect her. But as assailants descend on the city from all sides, keeping his promise proves to be no simple task. With turmoil rattling the kingdom, can this old knight survive his new post and keep his daughter safe? (Source: J-Novel Club)

Once a peerless Mechsteel pilot in his youth, Watt Sears is now nearing forty and working as a humble station employee. As a self-proclaimed “old man,” Watt has taken a liking to showing new pilots the ropes, choosing to support them however he can rather than stand in the spotlight himself. Despite the repeated pleas of his boss and the lord of the land to become a Steelrider—one of the elite monster-hunting mech pilots who keep the city safe—Watt is perfectly content with his quiet life. But all of that changes when his storied past catches up to him. Anna, his long-lost daughter from a bygone romance, appears before Watt one day to ask for his help. Resolving to keep her safe, Watt takes Anna under his wing—only to immediately find himself caught up in a not-so-bloodless battle for the throne. With the kingdom in turmoil, can this old knight survive his new post? (Source: J-Novel Club)

Year 20XX, strange phenomena started to occur all around Japan. The best way to explain it would be a ''hole'' that connects different worlds to our world. Many otherworldly beings - magicians, demons, robots and other fantasy creatures started to appear on this side, with no way to return. With the time passing, Japan was able to adapt to this event and visitors from another world stopped to be anything unusual. And so, an unlucky witch named Henrietta was pulled through the ''hole'' and ended in modern day Japan without a way to return. How will she be able to live in this different world? (Source: Bato.to)