It was April 3, 3901.
On the shores of Lake Tosmo in the Shouro Empire, major construction work was underway.
It was the construction site for the Adriana Memorial Hall (tentative name).
"Hmm, maybe I should increase the power a bit more..."
Jin, the Third Generation Magi Craft Meister who had commissioned the project, muttered to himself as he watched the laborers trying to move a massive boulder.
The workers were equipped with power assists for civil engineering and construction.
In essence, they were construction-oriented powered suits—or rather, power assists.
Since the machines were not suits of armor, the operators did not climb inside. Instead, they mounted them from behind, riding just behind the shoulders.
Each unit stood 2.5 meters tall and weighed roughly 600 kilograms.
To prioritize stability, they featured three legs.
The reason for three legs rather than four was simple: it drastically simplified the control system required to coordinate foot placement on the ground.
Lacking a head, the machine left the operator's upper torso positioned where the head would normally be.
A sturdy guard bar protected the pilot's head, strong enough that even a direct blow from a steel girder would not make it budge.
With roughly three times the strength of an ordinary human, the machines were perfectly suited for heavy labor that required no delicate precision.
"Oh man, this thing is incredible!"
"They said it's just a prototype, but work's flying by!"
"It was tricky to handle at first, but once you get the hang of it, it's a piece of cake!"
Operating the machine involved loosely linking one's arms from the elbows down and legs from the knees down to the frame.
Because of this setup, fine motor control was impossible.
The hands had no individual fingers, resembling mittens instead, which meant they could barely manage to grasp objects.
In other words, their functionality was limited to raising and lowering the arms, and grabbing or releasing items.
Even so, that was more than enough for hauling stones or carrying building materials.
The walking speed was capped at roughly a human's normal pace, eliminating any danger of the machine running wild.
These design choices were the direct result of ruthlessly stripping down the specifications to ensure the machines could never be adapted for military use.
Jin had loaned five of these power assists to the site free of charge.
On paper, it was a field test for a new magi-device, but in truth, it was meant to improve the efficiency of the construction work.
As noted, the primary reason for this specific configuration was to prevent military diversion.
—The operator's upper body was left completely exposed.
—The movement speed was limited to a standard human walking pace.
—The hands could barely manage to grasp objects.
Furthermore:
—Under continuous full operation, the mana cells required replacement every single hour.
Jin reasoned that unless someone rebuilt the entire machine from the ground up, turning it into something unrecognizable, it could never serve as an instrument of war.
Additionally, by simplifying the structure as much as possible and utilizing inexpensive materials, he had managed to keep production costs down to around 50,000 Toll.
That came out to roughly 500,000 Japanese yen—less than the price of a light car.
Of course, once technical fees and retail markups were factored in, the market price would typically triple, as was the way of the world. That would put it at 150,000 Toll, or about 1.5 million yen.
Still, considering that was roughly on par with a higher-end light car, Jin figured adoption would not be out of reach.
In fact...
"Man, I'd love to have one of these for myself."
"Yeah, tell me about it. It's a real lifesaver."
...voices expressing an eagerness to own one were already popping up here and there.
Jin had made it clear that because these were prototypes, they were not for sale.
However, he had also promised that anyone who provided feedback on flaws or defects would receive priority once mass production began, so the workers had been enthusiastically putting them through their paces.
Among the feedback gathered, the top three complaints (or perhaps the bottom three) were as follows:
It needs a little more power.
The walking speed is too slow.
Swapping out the mana cells so often is a pain.
Every single point was reasonable enough to make Jin nod in understanding.
"Then again, boosting the performance too much would defeat the purpose..."
As far as power went, if he spared no expense on muscle-type materials, the machine could easily deliver more than tenfold the output. However, the structural frame would not hold up, the controls would become far harder to manage, and production costs would inevitably skyrocket.
The same held true for the movement speed.
"As for the mana cells, maybe I should set them up to run two in parallel..."
Jin decided to compromise on that point, suspecting that end users would probably end up modifying that on their own anyway.
A mana cell was essentially a dry cell—or rather, a rechargeable battery. It could be recharged with mana using a mana server.
Installing more cells would extend the operating time... but he had no intention of letting it run for a full twelve-hour workday.
Even if it meant hardcoding the limitation directly into the control core, he was determined to keep it in check.
Once the day's work drew to a close, Jin inspected and serviced the power assists.
"Durability looks fine."
Since they were built for civil engineering and expected to endure rough handling, they had accumulated a few minor scuffs, but there were no structural dents or damage that would impair operation.
The wear on the joints and sliding parts was also well within acceptable parameters.
After completing routine maintenance on all five units, Jin turned his attention to addressing the reported issues.
"Increasing the power by about fifty percent should be easy enough."
Since the machines were currently operating at less than half their true potential, doubling their output would be a simple matter of rewriting the magi-sequence. However, concerned about the structural integrity of the frame, Jin decided to cap the increase at 1.5 times.
"I'll leave the movement speed as is."
A three-legged design made static balance simple, but dynamic balance was far trickier.
More accurately, the magi-sequence for three-legged locomotion was still crude, meaning that recklessly increasing the speed would be dangerous.
While the control logic itself was simple, the novelty of the design meant fine-tuning the various parameters took time.
"And for the mana cells, running two in parallel is definitely the right call."
If they could run for two hours at a stretch, the workers could simply swap them out during their scheduled breaks.
"That might even encourage better working conditions."
Making a minor tweak like that was effortless.
"Reiko, lend me a hand."
"Yes, Father."
Between Jin and Reiko, modifying all five units took barely ten minutes.
"That should do it. Let's see how they like them tomorrow."
Gazing over the newly modified power assists, Jin murmured in satisfaction.
Watching him, Reiko voiced a quiet question.
"Father, even without going to the trouble of building machines like these, wouldn't a single Smith be capable of outperforming more than five of these units combined?"
"Well, yes, that's true. But this project is about regional development, raising the baseline of technical skill, and stimulating the local economy."
"I see..."
Jin offered a nod.
In his role as the Third Generation, Jin had begun to focus on the widespread dissemination of magi-craft as his primary objective.
"The Second Generation focused heavily on demonstrating advanced technology and fostering a small, select group of specialists, after all."
Yet all of those achievements had ultimately been dismantled by the Magic Federation.
"It might sound unglamorous, but I believe that rather than just training a handful of experts, spreading the knowledge far and wide is the only way to ensure the tradition isn't easily broken."
"I understand."
Whether things would unfold as smoothly as Jin hoped remained to be seen.
Even so, Jin had resolved to do everything within his power to try.