Momoyama, Peach Mountain.
The air here was always crisp, carrying the faint, sweet scent of ripening fruit and the sharp, ozone tang of the storms that frequently rolled over the peaks. In the center of a small courtyard belonging to a weathered wooden house, a young man sat cross-legged on a smooth stone, a book resting forgotten on his lap.
"Ren... I'm back..."
The voice was less of a greeting and more of a rhythmic, miserable sob. Ren didn't need to look up to know who it was. The shuffling footsteps, the erratic breathing, and the sheer aura of despair were unmistakable.
Zenitsu Agatsuma had returned.
Ren closed his book and turned around, his expression shifting into a mask of weary sympathy. As expected, Zenitsu looked like he had been put through a meat grinder. His yellow haori was stained with dirt, his hair was a mess of twigs and leaves, and his face was a vivid tapestry of purple bruises and angry red welts. His left eye was nearly swollen shut, making his habitual tears leak out at an even more pathetic angle.
"Caught and dragged back again, I see?" Ren asked, his voice calm but tinged with a hint of helplessness.
"Gramps is a monster!" Zenitsu wailed, collapsing onto the porch steps like a puppet with its strings cut. "He's not a teacher, Ren! He's a demon! A cruel, heartless, white-haired demon! I was almost at the foot of the mountain! I could see the village lights! I could almost taste the freedom, and then bam! A cane out of nowhere! Ren, he hit me so hard I saw my ancestors waving at me!"
Ren sighed, standing up to retrieve a small jar of medicinal ointment from the house. His name was Ren, and in a previous life, he had been a cog in the relentless machine of Blue Star's corporate world. He had spent his days staring at blue-light filters and his nights drinking lukewarm coffee to survive unpaid overtime. His story ended when his heart gave out under the pressure of a seventy-two-hour shift.
When he reopened his eyes, he wasn't in a hospital or a cubicle. He was in the Taisho era, inhabiting the body of a boy named Tomoya, an orphan left to rot in the slums. He had met Zenitsu while they were both wandering the streets, two cast-offs looking for a scrap of warmth. They had formed a bond born of shared hunger and loneliness.
Then came the debt. Zenitsu, driven by a desperate, pathetic need for love, had been tricked by a girl into co-signing a loan that was effectively a death sentence. As the debt collectors closed in, Ren had been ready to fight a losing battle to protect his friend. That was when Jigoro Kuwajima had appeared.
The former Thunder Hashira hadn't just paid off the debt; he had claimed their lives in exchange, bringing them to Peach Mountain to forge them into blades for the Demon Slayer Corps.
The problem was, only one of them was a blade.
For the past year, Ren had tried everything. He had practiced until his palms bled and his lungs felt like they were filled with crushed glass. Yet, no matter how hard he pushed, he couldn't sense the "rhythm" Gramps talked about. He couldn't grasp the Total Concentration Breathing. To the old man's disappointment, Ren appeared to have absolutely zero aptitude for the sword.
Zenitsu was the opposite, a genius who refused to believe he was one. He had the talent to master the lightning, but the courage of a frightened hamster.
"Stay still, Zenitsu," Ren murmured, sitting beside the sobbing boy and dabbing the ointment onto a particularly nasty bruise on his cheek.
"Ouch! Gently! Ren, be gentle! You're supposed to be my best friend!" Zenitsu shrieked, flinching away even though Ren's touch was as light as a feather. "I can't do this anymore. I'm going to die here. If the training doesn't kill me, the demons will. Or maybe I'll just explode from pure stress! Why can't we just go back to the city? We could sell charcoal! We could wash dishes! Anything but this!"
Ren didn't answer immediately. He was looking at Zenitsu, calculating the timeline in his head. In the original story, Zenitsu only trained here for about a year before the Final Selection. Based on the blooming peach blossoms and the intensity of Gramps' recent "lessons," that time was almost here.
Ren felt a cold pit of dread settle in his stomach. When the time came, Zenitsu would be sent down the mountain. Even if he did it crying and screaming, he had the Thunderclap and Flash to keep him alive. But Ren? He was just a normal guy. In a world where demons could regenerate limbs and move faster than the human eye could track, he was nothing more than a liability.
Is this how it ends? Ren wondered. Die of overwork in one life, and die as demon bait in the next?
Suddenly, a sound echoed in his mind, not a physical sound, but a cold, crystalline chime that seemed to vibrate through his very soul.
[Host's desire to change his fate detected. Friend System is now binding...]
[Binding successful!]
Ren froze, his hand stopping mid-air. Zenitsu blinked at him, a tear hanging precariously from his nose. "Ren? Why did you stop? Did you see Gramps? Is he behind me?! Don't let him take me!"
Ren didn't hear him. His heart was racing as a translucent blue screen shimmered in his field of vision. A "cheat." It had finally arrived.
[Friend System Function: Establish a genuine friendship to obtain rewards from the target.]
[Rewards include: Comprehension, Aptitude, Talent, Abilities, and more.]
[Rule: The deeper the bond, the more rewards can be extracted.]
[Innate Ability unlocked: Inspect.]
I can gain strength just by being a friend? Ren's mind whirled. In a world as dangerous as this, a social-based system was a godsend. He didn't need to be a protagonist; he just needed to be friends with them.
He immediately turned his gaze toward himself, testing the [Inspect] function.
[Host: Ren]
[Race: Human]
[Rank: None]
[Comprehension: Inferior (Your mind is clouded by the mundane logic of your past life.)]
[Aptitude: Inferior (Your body is ill-suited for the rigors of Breathing Forms.)]
[Talent: None]
[Skill: Bandaging (Mastery - You've had a lot of practice with Zenitsu.)]
Ren's lip curled in a bitter smile. "Inferior." It was a harsh assessment, but an accurate one. No wonder he had spent a year failing to learn a single form. He was fundamentally "un-talented" by the standards of this world.
He turned his eyes to the shivering boy beside him.
[Name: Zenitsu Agatsuma]
[Race: Human]
[Rank: Mizunoto (Entry Level)]
[Comprehension: High (A natural instinct for the flow of lightning.)]
[Aptitude: High (Physically optimized for explosive speed.)]
[Talent: Enhanced Hearing (Absolute pitch; can read emotions from sound and distinguish between humans and demons.)]
[Skill: Thunder Breathing, First Form: Thunderclap and Flash (Mastery)]
The contrast was staggering. Zenitsu was a powerhouse in waiting, a masterpiece of potential hidden behind a curtain of cowardice. His mastery of the First Form was already at a level most swordsmen wouldn't achieve in a lifetime.
How do I trigger it? Ren thought. The system said verbal acknowledgment.
He looked at Zenitsu, who was currently trying to wipe his nose on his sleeve. Ren reached out and grabbed Zenitsu's shoulders, his expression becoming intensely serious.
"Zenitsu," Ren said, his voice dropping an octave.
Zenitsu jumped, his eyes widening. "Y-yes? Why are you looking at me like I'm a piece of premium steak? Ren, you're scaring me! You're not going to turn me in to Gramps for a reward, are you?!"
"Zenitsu, listen to me. We've been through hell together. We starved together, we froze together, and we've survived this mountain together. I need to know... we're friends, right? Real friends?"
Zenitsu went still. The frantic, high-pitched energy drained out of him, replaced by a rare moment of genuine vulnerability. He looked at Ren, seeing the person who had never judged him, never looked down on him, and always patched him up when the world broke him.
"Ren..." Zenitsu's voice trembled, and he nodded heavily. "Of course we are! You're the only person in the whole world who doesn't think I'm a complete waste of space! You're my only real friend!"
Ding--!
[Successfully added Zenitsu Agatsuma as a friend.]
[Detected Intimacy Level: 'Best Friend'. (The target trusts you with his life.)]
[You have unlocked 4 rewards from this target!]
[Acquired: Comprehension (High)]
[Acquired: Aptitude (High)]
[Acquired: Talent: Enhanced Hearing]
[Acquired: Skill: Thunder Breathing, First Form: Thunderclap and Flash (Mastery)]
[Would you like to merge the rewards now?]
Ren felt a surge of triumph so powerful it nearly made him dizzy. He had done it. With one sentence, he had bridged the gap that a year of agonizing labor couldn't cross.
Not yet, Ren commanded the system. He couldn't risk a physical breakdown in front of Zenitsu.
"Ren? You're smiling. It's a creepy smile. Why are you smiling like a villain?" Zenitsu asked, shuffling back a few inches.
"I'm just happy, Zenitsu," Ren said, patting his friend's shoulder. "I'm happy we have each other. Now, go inside and wash up. Gramps will be back soon, and you don't want him to catch you lounging around."
"Eek! Gramps!" Zenitsu scrambled to his feet, the fear of the old man's cane overriding his curiosity. He bolted into the house, leaving Ren alone in the darkening courtyard.
Ren stood up, his eyes reflecting the first few stars appearing in the sky. His journey had truly begun. Tomorrow, he wouldn't be the "talentless orphan" anymore. Tomorrow, the lightning would belong to him, too.