"I'm sorry, I'm sorry, I'm sorry—"
The young woman named Kohong kept her head down, apologizing over and over with red eyes.
"Ha? You think saying sorry is gonna fix this? Call your boss out here right now!"
Kaigaku stood there with an arrogant sneer, fully intent on making a scene.
Like Shuya, he had also been given a mission by the Demon Slayer Corps—to search Yoshiwara for any signs of demons and eliminate them. But unlike Shuya, Kaigaku knew his own limits. Yoshiwara was one of the most prosperous places in the entire country. If there really was a man-eating demon hiding here, it wouldn't be some weak Lower Rank.
If it was a Lower Rank, he could probably run. But an Upper Rank? He had zero confidence in surviving that.
So he deliberately picked a fight with this apprentice courtesan from Kyogoku House in broad daylight. His goal was simple—stir up trouble and force any hidden demons to show themselves. Even if nothing came out, the Corps would clean up the mess for him afterward.
As for whether this would piss people off? He didn't care. Staying alive was all that mattered.
"I'm sorry, sir! Please don't do this. I'll compensate you!"
Kohong panicked the moment she heard him demand to see the owner. Even though she was only an apprentice courtesan, she knew how badly this could end for her.
"Compensate me?" Kaigaku scoffed. "You think I need your shitty compensation? Hurry up and call your boss!"
"I'm sorry—"
Kohong could only keep apologizing. She was just a lowly apprentice. There was no way she could win against an armed samurai.
"Kaigaku?"
A calm voice came from behind him.
Kaigaku turned around, hand resting on his massive sword.
He saw a little girl, followed by a few strange people. One woman was clinging to a man's back with a ribbon covering the lower half of her face. Another figure was completely wrapped in a cloak. The only normal-looking one was the man carrying the woman.
"Pretty boy? You trying to play hero for her?"
Kaigaku looked Shuya up and down with clear disdain. "I don't know how you know my name, but don't think that means I'm scared of you."
Shuya didn't get angry. Instead, a small smile appeared on his face.
Kaigaku really was a born piece of shit. But he was also genuinely unlucky. Most people didn't know that before he became a Demon Slayer, he had a direct connection to Gyomei Himejima. In fact, Gyomei only joined the Corps because of what Kaigaku did.
Back then, Gyomei was a monk at a small temple that took in ten children, including Kaigaku. Life was peaceful but they were always hungry. One night, Kaigaku couldn't take it anymore and tried to steal the temple's money. The other kids caught him and kicked him out without telling Gyomei.
That same night, Kaigaku ran into a demon. Instead of dying, he made a deal—he went back and put out the wisteria incense, then sold out everyone in the temple. The demon kept its word and let him live. By morning, only one child remained, and Gyomei had beaten the demon to death with his bare hands.
Because of what happened, Gyomei was mistaken for a murderer and later recruited into the Demon Slayer Corps, eventually becoming the Stone Hashira.
Kaigaku, on the other hand, later joined the Corps himself and became Zenitsu's senior. He was even close to reaching Hashira rank before he ran into Kokushibo and got turned into a demon.
Shuya looked at him and asked, "Do you still remember Gyomei Himejima?"
Kaigaku's face twitched.
"I don't know what you're talking about."
He tried to play dumb, but cold sweat was already forming on his back. Gyomei was a nightmare he could never escape. The fact that the man he betrayed had not only survived but become a Hashira terrified him.
"No need to admit it," Shuya said casually. "I don't really care either way."
He turned to Gyutaro and released the chains binding him.
"Go. Teach him a lesson."
Gyutaro blinked in confusion for a second, then looked at Daki on Shuya's back. She gave him a sharp nod.
"Got it."
Gyutaro ripped off the cloak and charged forward with two blood sickles in his hands.
Kaigaku's eyes widened when he saw the green-haired demon rushing at him.
"A demon?!"
He immediately drew his Nichirin Blade and used Thunder Breathing to block. But even with Gyutaro holding back, the force behind each strike made his arms go numb.
This wasn't some ordinary demon.
Kaigaku quickly realized he couldn't win. He glanced at Shuya, then made his decision.
"Thunder Breathing, Fourth Form—Distant Thunder!"
He flashed forward, not toward Gyutaro, but straight at Shuya. If he could kill the man giving orders, or at least use him as a hostage to escape, he might survive.
Shuya watched him approach without moving.
At the last second, he flicked one finger against Kaigaku's descending blade.
Ding!
The Nichirin Blade snapped cleanly in half.
Kaigaku froze, staring at the broken sword in his hands.
"…It broke?"
Before he could process what just happened, he dropped to his knees.
"I was wrong! Please don't kill me!"
His voice was desperate.
"I can be useful! I'll spy for you inside the Demon Slayer Corps. I can help you find their headquarters!"
Shuya stared at him for a moment, genuinely surprised by how fast the man folded.
"…You really are something else."
Kaigaku kept his head down, smiling obsequiously. "Yes, yes, whatever you say, sir."
Shuya pulled out a small vial and tossed it to him.
"Drink it."
Kaigaku caught the bottle with shaky hands. "Sir, this is…?"
"Demon blood."
Kaigaku's face went pale.
Shuya's tone was cold. "Drink it. I need you to awaken a Blood Demon Art that can control lightning. Since you use Thunder Breathing, that shouldn't be too hard for you."
Kaigaku swallowed hard. He had no choice. He uncorked the vial and drank it in one go, forcing himself to maintain Thunder Breathing's rhythm even as pain tore through his body.
Black lightning began crackling around him.
His teeth sharpened. Dark markings spread across his face. Within moments, he had fully transformed.
Kaigaku clenched his fists, feeling the overwhelming power surging through him.
"This… this is demon power? It's incredible!"
Shuya didn't give him time to enjoy it. He held out a glowing parchment.
"Equivalent Exchange. Give me that Blood Demon Art."
Kaigaku's expression changed instantly. For a brief moment, black lightning flared violently around him as he considered fighting back.
But fear won.
He dropped to his knees again.
"…Yes, sir. This power was given to me by you anyway. It's only right that I return it."
A sphere of black lightning left his body and flowed into Shuya.
Shuya flexed his fingers. Black sparks danced across his fingertips.
Finally. Black Lightning.
Kaigaku watched in shock. This man could even steal Blood Demon Arts? Just who the hell was he?
Shuya didn't explain. He manifested several chains and quickly built a wooden box around Kaigaku, sealing him inside with Nen.
"I'm not going to kill you," he said. "But I can't have you running around during the day either."
He picked up the box and casually threw it far into the distance.
Then he turned his attention back to the girl still clinging to his back.
"So? Have you made up your mind, Daki?"
Daki stared at him with shining eyes.
This man could give people demon blood. He could take away Blood Demon Arts. He could walk in sunlight and eat normal food.
He was even more perfect than Muzan.
And he was willing to let her have those things too?
She pressed her face against his neck, heart racing.
"Then there's only one answer."
She licked his ear once, unable to hold back her excitement.
"I swear my loyalty to you… my master."