Chapter 23: Never Advise Others to Be Good Unless You

Perhaps because he had drunk too much, Rengoku Sakonji sat across from Zero and chatted with him, and as they talked, he burst into tears—alcohol reveals the truth.

Only then did Zero learn what Rengoku Sakonji’s past had been like.

According to Rengoku Sakonji himself, the Rengoku family had been Flame Hashira for generations, and he was no exception.

In his youth, Rengoku Sakonji had been a cheerful, fiery-tempered man.

He mastered his family’s ancestral Flame Breathing technique and, through his formidable strength, became the Flame Hashira.

He traveled far and wide, slaying demons that plagued the land and protecting people’s lives and property.

Decades ago, Rengoku Sakonji married a woman named Rengoku Ruka, and together they had two sons: Kyojuro and Senjuro.

During the day, Rengoku Sakonji hunted down evil and punished wrongdoers; his wife, Rengoku Ruka, managed the household and raised their children. Their family was happy and harmonious, living a blissful life.

To uphold the Rengoku family’s ancestral teachings, Kyojuro and Senjuro began training under their father from childhood, practicing Flame Breathing and its corresponding sword techniques, with the goal of one day inheriting Sakonji’s position as Flame Hashira.

Of the two brothers, the elder, Rengoku Kyojuro, possessed extraordinary talent and, influenced since childhood by his father’s optimistic nature, became an inherently cheerful and bright person.

The younger brother, Rengoku Senjuro, had no talent for swordsmanship and grew up with a more pessimistic disposition.

Yet Rengoku Sakonji never abandoned his efforts to guide him, constantly encouraging him to become a useful man.

However, shortly after giving birth to their younger son, Senjuro, Ruka’s health deteriorated, and she eventually became bedridden—but she still insisted on personally teaching Kyojuro and Senjuro.

A few years ago, while on a mission to Hachijo Island, Rengoku Sakonji accidentally encountered a child who had nearly been killed by a half-woman, half-snake demon.

Fulfilling his duty, Rengoku Sakonji immediately used Flame Breathing sword techniques to effortlessly slay the snake demon and save the boy.

Yet when Sakonji took the boy to find his only surviving relative—his cousin—the cousin cursed him bitterly.

Just as Rengoku Sakonji was about to leave, the boy begged him to take him into the Demon Slayer Corps.

Though puzzled, Rengoku Sakonji still agreed.

The boy’s name was Ikki Kobanai—the current Snake Hashira of the Demon Slayer Corps.

Not long after, a girl named Kanroji Mitsuri joined the Demon Slayer Corps in search of her husband. Rengoku Kyojuro recognized her potential and adopted her as his foster daughter.

She later switched to the Flame Breathing offshoot, Love Breathing, and became the Love Hashira of the Demon Slayer Corps.

But soon after, Rengoku Ruka’s condition suddenly worsened, and she passed away.

Devastated by the sudden loss of his beloved wife, Sakonji was shattered and fell into despair.

He resigned from his position as Flame Hashira, withdrew entirely from public life, and began drinking daily to drown his sorrows—even ceasing all sword instruction for Kyojuro and Senjuro.

Yet strong-willed Rengoku Kyojuro did not lose heart because of his father’s self-destruction.

He taught himself using his family’s three ancient Flame Breathing manuals and eventually succeeded his father as Flame Hashira…

As he spoke, Rengoku Sakonji wept again, saying: “Zero, am I worthless? My two sons look up to me, yet now I’ve sunk so low…”

He then picked up the bottle and took another large gulp.

Zero, seeing this, offered no comfort: “Mr. Rengoku, I don’t think you’re at fault. On the contrary, you’re this way because you loved your wife too deeply.”

Hearing Zero’s words, Rengoku Sakonji looked up, astonished.

“Mr. Rengoku, never advise someone to be good unless you’ve walked their path. I cannot understand your pain, so I will not offer you advice or comfort.”

“Instead, the reason you’ve become like this is surely because you loved your wife deeply! I believe your wife must be both happy and heartbroken.”

“Why say that?” asked Rengoku Sakonji.

“Happy, because she found a husband who loved her more than himself. Heartbroken, because she left too soon, unable to stay beside the man she loved and her children, watching him fall apart because of her absence.”

Zero’s words struck Rengoku Sakonji deeply, stirring something strange within him. Many had tried to comfort him before, but he had refused to hear any of them.

Yet Zero said he had become this way because he loved his wife deeply!

Thinking back, he realized: during his years as Flame Hashira, after marrying Ruka, he had always been on missions, never truly staying by her side.

Yet she never complained. She stayed home, raising their children, waiting for his return.

Every time he came home, Ruka would say, “Husband, welcome back,” filling his heart with joy.

Recalling these moments made them feel as if they had happened yesterday, images flashing through his mind.

“Mr. Rengoku, since you loved your wife so deeply, I believe she is still beside you, unseen, always watching over you.”

This time, Rengoku Sakonji felt as if struck by sudden clarity—he had, since his wife’s death, ignored his two sons and neglected his family entirely.

But now he understood: the dead cannot return, yet perhaps, as Zero said, she truly was still with him, unseen…

Drinking with Rengoku Sakonji, he hadn’t realized how late it had grown until nightfall.

Now, Rengoku Sakonji was drunk, mumbling repeatedly: “Ruka… I miss you so much…”

Zero sighed helplessly—he truly loved his wife down to his bones.

At that moment, the room’s door opened, and the tavern owner entered with a boy who bore a striking resemblance to Rengoku Sakonji.

“Sir, this is Rengoku Senjuro, the son of Mr. Rengoku. The boy came looking for his father—he hadn’t returned all day.”

At first, the tavern owner thought Zero was a girl—until Zero told him he was male, and the owner realized his mistake, then apologized by adding extra snacks.

Looking at the young boy before him, Zero remembered from his conversation with Rengoku Sakonji that he had another son, seven years old, named Rengoku Senjuro.

“You’re Rengoku Senjuro, then!”

“Yes, I’m sorry my father has troubled you! I’ll take him home now.”

“No problem. I’m about to head out on a mission—I’ll help you take him home.”

“Thank you so much!”

“You’re welcome.”

Zero turned to the tavern owner and said: “Owner, thank you for your hospitality. The snacks were delicious.”

“You’re too kind, sir. I loved the liquor you gave me. If you ever have time, please come again.”

“I will.”

Together with Rengoku Senjuro, Zero helped lift the drunken Rengoku Sakonji and left the tavern.

I… am not drunk… keep… keep drinking… burp… let’s keep… burp… drinking…

Rengoku Sakonji, drunk and loud, slurred his words, stumbling as he was carried along.

“I’m sorry—my father always acts like this when drunk. I’ve troubled you.”

“It’s fine,” Zero said helplessly. He couldn’t imagine how such a small child had ever managed to drag his father home from the tavern—what a burden this boy had carried.

At the tavern’s entrance, Zero took out the [Dark Alloy Armored Vehicle] from his [Nanospace].

With a loud *boom*, the [Dark Alloy Armored Vehicle] landed on the ground. Everyone nearby jumped, rushing out to see what had happened.

Even the tavern owner was startled, eyes wide, mouth agape, speechless.

Rengoku Senjuro stared, dumbfounded, at the massive white behemoth before him.

Zero and Rengoku Senjuro carried the drunken Rengoku Sakonji to the rear compartment, opened the door, and laid him on the seat.

“Senjuro, stay with your father here. I’ll drive you home—it’s more convenient.”

“Oh… okay, thank you… by the way, may I ask your name…”

“I’m Zero.”

“So you’re Zero! The Demon Slayer Corps’ Zero Hashira!”

“You know me?”

“Yes. My elder brother often tells me about you. He says you’re incredibly strong—even single-handedly exterminated an Upper Moon demon! If only I could be as powerful… then perhaps Father…”

“Senjuro, I believe that day will come. One day, you will grow strong too.”

“Thank you, Mr. Zero.”

“Just call me Zero.”

“Then I’ll call you Zero-nii.”

“Uh… fine, whatever,” Zero said helplessly. It didn’t matter—he’d already been called that by Tanjiro. One more wouldn’t hurt.

“Stay with your father. I’ll drive you home.”

“Yes, thank you, Zero-nii.”

Finally, Zero opened the driver’s door, started the vehicle, closed it, and drove the father and son home.

The car sped off swiftly, vanishing before the stunned gazes of onlookers.

After about ten minutes, the vehicle stopped at the Rengoku residence. Zero stepped out from the driver’s seat, went to the rear compartment, opened the door, and helped Rengoku Senjuro carry Rengoku Sakonji inside.

“Zero-nii, thank you so much!”

“Don’t mention it. I must leave now—I still have a mission. I can’t stay long.”

“Understood. I’m sorry I can’t properly host you. Please come again when you have time—I’ll make sure to treat you well.”

“Thank you. When your father wakes, please give him my regards. I’ll take my leave now.”

“Yes, Zero-nii. May your martial fortune be great.”

Under Rengoku Senjuro’s watchful gaze, Zero drove away from the Rengoku home, heading toward his assigned territory.

…………

Several days later.

In the early hours, a demon was sprinting desperately, his eyes filled only with terror and despair.

He feared that if he slowed even a step, he would die without a grave.

Originally, there had been four of them—but the other three: one had been beheaded outright, another cut in half at the waist and then beheaded, the last severed at all four limbs before being beheaded.

Worse still, their wounds refused to regenerate.

The remaining demon, who had been on lookout, had fled immediately upon seeing the carnage—hence his current escape.

As for why… the story goes back half an hour.

Half an hour earlier, these four demons had found a remote cluster of homes, driven by unbearable hunger.

For days, they had kept changing hiding places, but it had done them no good.

The other ghosts had been hiding safely, but somehow the ghost hunter found them with ease.

His methods of torture weren’t human at all—they were demonic, and even calling him a demon felt too gentle; death itself was a better fit.

The ghost hunter held a two-meter-long, pitch-black scythe, its blade glowing with a crimson red light; dressed entirely in black, he looked like Death itself coming to claim souls.

Even in daylight, he could locate ghosts, drag them out, and throw them into the sun.

If they resisted, he’d strike them with a strange gun that paralyzed them into unconsciousness, then drag them out and toss them into the sun…

Tonight, the four of them were so starving they decided to take one last gamble: as long as they could eat their fill, they’d flee immediately afterward.

The moment they burst through the door, ready to devour the people inside, a streak of crimson light flashed—three ghosts were decapitated, one cut in half at the waist, another torn apart at the limbs…

The ghost on lookout panicked, unleashing all his strength to flee—he no longer cared about hunger; he just wanted to escape this place…

He ran until he stopped, stumbled, and collapsed to the ground, staring at the ghost hunter just ahead—the crimson eyes, the glowing red scythe blade…

Seeing this, he trembled uncontrollably.

“Keep running, it’s fine—I don’t care how long you run. I’m not done playing yet!”

Zero held the scythe in one hand and bit into an apple with the other, stepping slowly toward the ghost.

“A ghost!!!” The ghost couldn’t bear it anymore and screamed, scrambling to his feet and bolting backward.

Thud!

The ghost didn’t notice the tree behind him—he crashed straight into it and collapsed, unconscious…

Zero: “(?_?)”

Zero, slightly baffled, walked up to the ghost and poked his body with the scythe’s handle—turns out he really had passed out, his head bleeding from the impact…

“Wait, he’s a ghost himself… How embarrassing! Pfft!”

He spat at the ghost, finished eating the apple, then dragged the ghost by one leg to a tree facing the sunrise.

From the [Nanomaterial Space], he pulled out rope and tied the ghost to the tree, then leapt onto the trunk, took out a notebook and pen, and began writing his diary:

【X Month X Day, Dawn, Weather: Heaven sneezed.】

【This dawn, I encountered four more ghosts. Three were already dead. The last one tried to run but accidentally slammed into a tree and passed out! That’s bad enough—but before passing out, he screamed “A ghost!!!” What an embarrassment! He’s a ghost himself…】

【And am I really that terrifying? Do I really scare people into running? I just wanted to play with them a little longer… Sigh～╮(︶﹏︶)╭】

At the end, he drew a sighing face. By then, the sky had begun to lighten with the first pale glow of dawn.

As the sun rose, its light fell upon the ghost.

But the ghost felt no burning pain—instead, for the first time, he found the sunlight warm, radiant, and brilliant.

“Finally… free!” The ghost smiled as he turned to ash and dissolved into the air.

Zero: “…”