Slave Walker
"I told you earlier, didn't I? Free skin care service. It's just a simple depilation, so don't worry about it too much. Now then — next, I'll insert the Slave Walker control unit."
"Y-yes… Yes… Miss Peko… W-wait a moment! I-insert…?!"
"That's right. From now on, just relax, keep your eyes facing straight ahead, and you'll be fine."
"B-but just a moment ago you said all I had to do was stay inside…"
Her voice trailed off, but even Sonia herself had a vague sense that a weapon the size of a car wasn't going to move on its own just because she stood there quietly.
What she'd imagined was something more like sitting in a cockpit and pressing a few buttons.
From the beast-like posture that had forced Sonia's knees to the floor, the robotic arms began — slowly, with irresistible strength — to ease her legs apart.
> Inserting Slave Walker control unit.
With a low mechanical whine, another robotic arm appeared behind Sonia's back.
Clutched at its tip was a slender, rod-shaped transparent device that looked to be made of soft medical-grade silicone.
"…What? I-insert…?"
The Slave Walker control unit. Without hesitation, the robotic arm began slowly — then firmly — pushing the device into Sonia's most private place, now smooth and bare of even a single soft hair.
"Hngh?! Nnh…♡ Haa… Haaah…♡ Hhk…♥"
The sensation of something cold and rubber-tube-like driving into the deepest part of her body. The sounds that burst from Sonia's lips began as something close to shock and surprise, but as the foreign presence sank deeper and deeper, they transformed into sweet, lewd cries of pleasure.
"Now that you can move, we'll get started right away!"
Peko's voice came through like a formal notice, but Sonia no longer had the presence of mind to answer.
> Slave Walker — system initialization complete.
> Slave Walker — unit synchronization complete. Connecting control frame… External controller connection confirmed. Ready for operation.
"Sonia, can you hear me? From this point on, you're going to move for real."
"I can hear… you… Something about a slave… Nnh, saying weird things like that… making a person feel so embarrassed… Is this really right…?"
Even with a foreign object clearly inserted into her most precious place — a "controller," no less — Sonia didn't get angry. She simply asked back with the same gentle, composed demeanor as always.
Thanks to the calming patch stuck to her forehead, sharp pain and discomfort never came. Instead, only the soft, slick sensation of something filling her from within dominated her brain.
Peko's voice, which until now had come from right beside the Walker, now reached her even more clearly and closely through the speakers inside the machine.
"I'll keep the explanation simple. From now on, Sonia, you'll be responsible for this Walker's posture control."
With a low thrumming vibration, the interior of the Walker brightened just a little more with a soft click.
"The principle is that the Walker moves exactly the way you move, so just watch the screen and follow along. Doing it yourself will be faster than explaining. Switching to control mode."
"Nnh… Yes… Miss Peko…"
When Peko pressed a single button on the controller, the scene before Sonia's eyes transformed dramatically.
The Walker's front section, which until moments ago had looked like nothing more than black steel plating, turned transparent as glass and began projecting the outside world beyond the Slave Walker in real time.
The contact lenses embedded in Sonia's pupils received the vast visual data transmitted from the external sensors and projected it directly onto her optic nerves. Sonia was now seeing the world through the eyes of the Slave Walker.
(Oh… Ohh… Amazing… Nnh…♡… Of course, looking at all the wrecked buildings everywhere, I can't exactly celebrate…)
"All right then… first… can you try standing up, Sonia?"
"C-can I stand up? In this position? Nngh… Nnh…!"
As Sonia tried to raise her upper body from her prone posture, she felt a sensation as if her body were floating lightly upward.
The external view reflected in Sonia's vision — the Walker's vision — tilted smoothly upward as well, as though a massive steel beast were lifting its head.
"You're doing well. Just like that — try moving your hands and feet a little, too."
"Yes…! If I do it like this… Wow… This is really incredible…"
The robotic arms binding Sonia's limbs didn't hinder her movements — they followed along gently, assisting her.
When Sonia crawled forward on all fours, the conveyor belt beneath her feet moved in the opposite direction, always keeping her position fixed at the center of the Walker.
Those same movements transferred directly to the Slave Walker's four steel legs, driving the massive machine forward.
Ugh… That thing fitted inside me… is so ticklish… Nnh… But still…
With every movement, the control tube lodged firmly in her bare, smooth intimate cleft stimulated her from within, stirring a strange pleasure.
This chaotic world where monsters and superhumans coexisted had, paradoxically, given rise to an extremely open culture around sex.
The adult video service on Nebulix, which Sonia paid a monthly subscription for, was raking in enormous wealth, and membership SM clubs and brothels run by succubi thrived throughout the city.
In a world like that, what Sonia was experiencing right now might not have been all that special. The only thing that made everything different was the fact that it had become reality — happening directly to her own body.
"Connection status is normal… You're doing very well, Sonia. From now on, move the Walker according to the instructions I send you."
Peko's voice, laced with a cold mechanical tone, resonated through the communication device fitted to Sonia's ear. It carried an authority that could not be refused, as though it were whispering directly into the deepest part of her brain.
"The instructions will be delivered as direct sensations through the device connected to your body. Like this. This feeling. This is the command to go forward. Remember it well."
The moment Peko finished speaking, Sonia's body flinched in response. It wasn't a simple voice command. It was a primal, instinctive signal engraved directly onto Sonia's nervous system.
"Yes, Mas… Ah…? Uh… Miss Peko…"
A word of submission that slipped out on its own. Master. The moment it left her lips, Sonia's cheeks flushed faintly red.
It was clear evidence that the cool-textured calming patch fixed firmly to her forehead had begun to take effect.
Minute nano-particles flowing from the patch entered her bloodstream and traveled to her brain, gently numbing Sonia's unnecessary resistance and personal sense of self.
Complex, inefficient thought circuits were forcibly shut down by the system. Things like her sense of duty as a hero, her personal anxieties, her worries about the future — all of them faded into a distant, hazy fog.
From the cold metal of the Slave Walker, only the physical sensations of her own body — now reduced to a single component — were amplified to an abnormally sharp and vivid degree.
It was a forced mental modification procedure designed to make her perceive herself not as a complete person, but as a living organic part of the Walker.
Originally, this function had been an inhumane system installed to forcibly control captured criminals or uncooperative Slave Units paralyzed by extreme terror, and to raise their synchronization rates.
Ironically, the system applied the exact same procedure — without a single second of hesitation or exception — to a D-class hero girl who had come of her own free will to cooperate in protecting Sky City. Machines knew neither mercy nor exceptions.
…I'm inside… a Slave Walker right now… so then… what exactly am I… right now…? No… Th-this isn't the time to be thinking about that…!
While Sonia moved her smooth limbs little by little, privately marveling at the perfect synchronization with the Walker, Peko wasted no time beginning the real control training.
Peko's slender fingers gripped the controller. Among its parts, she gently pushed the joystick responsible for movement forward with her thumb.
The electrical signal generated by that minute motion transferred to Sonia's body at the speed of light. The cold metal choker wrapped around Sonia's delicate neck was pulled forward — gently, but with irresistible force — as though guided by an invisible master's hand.
"Hyaah…?! M-Miss Peko… Is this normal… Nnh…♡ This is normal… right…?♡"
At the same time that a humiliating sensation of being choked climbed her spine, the transparent polymer control rod lodged deep in Sonia's vagina — all the way to the entrance of her womb — also shifted slightly forward.
The tip of the control device found the most sensitive, softest membrane inside her with perfect precision and stimulated it. Pleasure and the sensation of submission mixed together, turning Sonia's mind white.
On a fierce battlefield where even the smallest movement could mean life or death, the system had never considered the human rights or dignity of its boarding unit in the first place.
It had been designed so that a signal-transmission device inserted into the most sensitive and primal part of the body would make instinct react before rational judgment ever could. Because it was the most certain — and the most efficient — method of control.