Demon Slayer: Start With Heroic Spirit Legacy System

Hachijōjima Island

The Iguro Family Dungeon

The Iguro family had not seen the birth of a boy in over 300 years.

Outsiders whispered that the family was cursed, destined to never have a male heir.

But twelve years ago, on a fateful night, little Obanai was born.

He had a pair of heterochromatic eyes—left green, right gold—strikingly beautiful.

When his mother and elder sisters first saw the newborn Obanai, their initial reaction was one of terror.

But that terror quickly gave way to joy.

"At last!"

Even as a newborn, Obanai could remember his mother's exclamation.

He was the first male child of the Iguro family and, from the moment of his birth, was confined in a pitch-black underground cell.

The Iguro family's dungeon was a massive wooden structure beneath the earth.

Every beam was several times thicker than Obanai's arm, coated with an expensive lacquer that even the wealthiest families would hesitate to use for such purposes.

And Hachijōjima Island was far from wealthy.

Obanai, however, didn't care about any of this.

"This is just a place to live. Mother and my sisters will take me outside one day."

The dungeon was filled with incense and illuminated by large, crimson candles.

The vibrant red wooden walls were carved with twisting, obscure inscriptions, seemingly some kind of sacrificial markings.

Every day, his mother and sisters brought him lavish, sumptuous meals, their faces always adorned with strange smiles.

Obanai detested these offerings—hated them to his very core.

Something deep inside him sensed they were unclean.

He had never experienced familial love, yet something instinctual told him: This isn't love. It's compensation.

"Why are they compensating me?" He often pondered this question.

He never considered escaping.

"Why should I escape? What does escape even mean?" His isolated existence left him utterly ignorant of the world.

He didn't dislike his living quarters, safe from the unsettling sounds of massive creatures writhing above the ceiling at night.

He was lonely, utterly alone, with not a single companion.

Until one day, he discovered a small white snake in his cell.

He named it Kaburamaru, and from then on, the boy and the snake relied on each other for company.

Life, though monotonous, became bearable.

He remembered every day he had lived and kept them close in his mind.

Today was his twelfth birthday.

Outside the dungeon, the atmosphere was unusually lively, with the Iguro family women murmuring among themselves.

"He's twelve now. It's time to offer him to that being."

"Let's hope the honored one is pleased."

"With this, I can buy more jewelry and accessories!"

"I want more money!"

His keen intuition told him that their conversation was about him.

"Kaburamaru, what do you think the world outside is like?"

Hiss, hiss.

Kaburamaru flicked its tongue, producing sharp, hissing sounds.

"Big? How big? As big as ten of these rooms?"

HISSS!!!

"Bigger than that? Then… a hundred rooms?"

Their little exchange was cut short.

A group of Iguro family women entered the cell.

Kaburamaru swiftly slithered into the bedding to hide.

"Get up! Mother is taking you to meet the honored one."

And just like that, Obanai was taken away.

The once-inaccessible dungeon exit was now within his reach.

For the first time in his memory, he was leaving the confines of his prison.

The world outside was far larger than he had imagined!

Now he understood Kaburamaru's meaning—it wasn't just a hundred times bigger. It was countless times more expansive!

"So bright! This must be the sky Kaburamaru was talking about."

The air outside was fresher, free of the greasy, heavy scent of the dungeon.

If only I could stay out here forever, Obanai thought, a sudden wish forming in his mind.

But his mother's grip on his left hand tightened painfully.

This woman, whom he called mother, paid no heed to his discomfort, urging him forward.

"Hurry! Don't keep the honored one waiting!" she snapped, her face strained with a forced smile.

They passed through intricate and extravagant courtyards until Obanai was led into an even more luxurious building.

The moment he stepped inside, every pore in his body tightened, and his hairs stood on end.

A primal fear, etched into human instincts, screamed at him to run.

But it was too late. Pushed and prodded by the surrounding women, Obanai was ushered in.

The Iguro family members stood respectfully on either side of the room, and in the center of a raised platform lay a colossal creature.

It had the body of a snake and the face of a human. Its massive form coiled on the steps, its gaping mouth exuding a nauseating stench of decay.

Demon! This must be a Demon!

The creature crawling and wriggling on the ceiling every night—it's it!

The "Monster" that the villagers always mention—it's also it!

Little Obanai's eyes were wide with fear, her limbs stiff and ice-cold, unable to move at all.

"Oh? What have you brought me this time? If it doesn't please me, I won't give you any jewels."

The massive snake monster spoke.

Little Obanai trembled uncontrollably, unable to utter a single word.

"Save me!"

That was the only thought in her mind.

Shamefully, Zhou Yi had gotten lost. After several twists and turns and slaying a few lesser demons, he had finally made it here.

"This is really bad. What was supposed to take two days ended up taking seven."

"I wonder how Senior Sister is doing. Takinogawa Village? Is it a village full of beautiful sisters?"

Zhou Yi was frustrated. It was all because of that demon he encountered a few days ago!

It was weak as hell but had the audacity to have the mark of a Lower Moon demon in its eyes. Its ability to make people lose their sense of direction was just annoying.

To repay this demon for its "great virtue and kindness," Zhou Yi had mercifully sent it to the afterlife, where it could befriend Yoriichi Tsugikuni.

"Just a few slashes and it was done. This thing dares call itself a Lower Moon? Shameful!"

"Shameful! Shameful!" The kasugai crow that had just flown back from the Demon Slayer Corps headquarters squawked, comically mimicking Zhou Yi's tone.

Zhou Yi's face darkened. This talkative crow had gone to deliver a message but took forever to return.

"No, I need to find a local to ask for directions."

However, this Hachijojima Island was desolate and run-down, with abandoned houses everywhere. Zhou Yi wandered for a long time before finally spotting an old farmer.

"Excuse me, sir. Can you tell me how to get to the Iguro family on Hachijojima Island?"

At first, the old man seemed normal, but the moment Zhou Yi mentioned the Iguro family, he shuddered violently.

"The Iguro family!! Young man, why are you asking about them?" The old man's face turned pale with terror.

At just 12 years old, Zhou Yi already stood an impressive 1.7 meters tall. In this era of Japan, he was exceptionally tall and could easily be mistaken for an adult.

The old farmer cautiously looked around to make sure no one else was nearby before continuing, "That family is strange! You'd best not go there."

Strange?

Zhou Yi raised an eyebrow, thinking to himself, Strange? Strange is perfect! If it's not special, what's the point of coming here?

Feigning confusion, he pressed further, "Sir, can you tell me more about it?"

As he spoke, Zhou Yi casually handed over a small piece of gold.

This system of his wasn't great in many aspects, but it was rich! After slaying that Lower Moon demon, he had unlocked an entire treasure vault.

"Just a little token of my appreciation, sir. Please accept it."

The old man's eyes lit up at the sight of the glittering gold, but he still hesitated, furrowing his brows. After some internal struggle, he managed to resist the temptation.

There's hope! But I need to offer more!

Without showing any frustration, Zhou Yi took out a larger piece of gold.

"Don't worry, sir. I won't tell anyone. A handsome young man like me? How could I lie to you? Trust me!"

Finally, the old man relented. "It's not about the gold—it's fate that brought us together. Just don't tell anyone!"

After a furtive glance around, he quickly pocketed the gold, holding it tightly against his chest.

"Of course, I understand." Zhou Yi smiled faintly, completely unbothered.

"It's said that the Iguro family worships a giant snake monster! They attack passing merchants and travelers to rob them of their wealth."

"Why would a snake monster need money?" Zhou Yi asked knowingly.

"The snake monster doesn't, but the Iguro family does! They offer infants in exchange for vast riches! I've heard they're filthy rich—so rich they even lacquer the wood in their prison cells!"

"Even the city officials can't afford that!"

!!!

The kasugai crow perched on Zhou Yi's shoulder felt a wave of killing intent and flapped its wings in panic, awkwardly flying away.

The old man, noticing Zhou Yi's dark expression, quickly asked, "Young man, are you alright?"

"Oh, I'm fine, sir. Can you point me in the right direction?"

"That Iguro family is so audacious. I think I'll go have a little 'chat' with them today!"

The word chat practically hissed through Zhou Yi's gritted teeth.

Such outrageous acts—he had mentally prepared himself, but this level of atrocity still ignited a flame of fury in the young man's heart.

"Young man, don't be reckless! You'll lose your life!"

"Hah! If I'm not reckless, what kind of young man would I be?"

Seeing Zhou Yi's reckless determination, the old man stopped trying to dissuade him and pointed in a direction.

"Just keep going straight ahead, but you'd better be car—"

Before he could finish, a strong gust of wind swept past. Zhou Yi had already vanished.

"Huh? Where did he go?"

If it weren't for the heavy gold in his arms, the old man might have thought he'd encountered a ghost.

"Well, with this money, I won't stay here any longer. I'll pack up and leave."

"It's just a shame about my poor, unlucky child…"

For those still living on Hachijojima Island, if not most, then at least all of them bear a grudge against the Iguro family.