Anime: Passive Inheritance System

Aincrad 39th Floor

The reddish-gold sunset bathed the white stone buildings in the safe zone in warm light. Above the infinite sky, golden clouds drifted lazily.

It had been two weeks since the raid team reached Floor 39. In the main street of the town, a few well-equipped players lingered. At this stage, most of them were high-ranking players, even if not in the raid team.

At the end of the stone road near Norvret's teleportation plaza, the sound of stringed instruments floated softly, drawing a small crowd of five or six players to listen.

Though SAO didn't have background music during combat, every floor's teleport plaza had an NPC orchestra that played endlessly, day and night.

But today's performance had something different—faint singing mixed with the usual orchestral melody.

Since SAO's code didn't allow NPCs to sing, it was clear the voice came from a player trapped in this death game.

Past the listening crowd, a female player stood beside the NPC musicians, hands folded at her chest, softly singing.

Her white hood concealed most of her face, revealing only pale pink lips that moved gently. Her voice was quiet, yet perfectly balanced with the light melody, bringing a peaceful calm.

The lyrics were in Japanese and harmonized with the NPCs' music. Her clear, delicate voice carried a soft loneliness, like someone journeying alone.

The high-level players listening nearby closed their eyes, swaying to her song.

They were among the strongest in Aincrad—many not in the official raid group but still survivors of countless deadly battles. The pressure they endured was immense.

But at this moment, her singing washed over them like a wave of release.

The clear voice continued for two or three minutes before the girl stopped. She lowered her hood slightly, nodded politely to the onlookers, then ducked out of the plaza and disappeared through the blue teleport gate.

Only after her figure vanished did the players begin to applaud and chat softly, smiles appearing on their faces.

Off to the side, leaning casually against a wall, a light-armored swordsman in a black coat watched her with interest. A faint smile played on his lips.

"...Quest target, found."

After watching the teleport gate for a moment longer, the black-clad swordsman straightened up, gripped his sword hilt, and walked toward the labyrinth zone.

Leaving the safety of the circle, passing through peaceful forests and grasslands, Kai arrived at the entrance to the labyrinth zone located on a flat plain in the northeast of the floor.

With a pale blue longsword loosely held in one hand, Kai walked calmly across the plain, like a man on an afternoon stroll. The artificial breeze simulated by SAO's weather system brushed past him, making the hem of his black coat flutter and rustle in the wind.

It had been five days since he first entered Aincrad. During that time, starting from the Town of Beginnings on Floor 1, Kai had used the advantage of his backdoor account to rapidly catch up to the current frontliners, reaching Floor 40, which was in the midst of being conquered.

And soon, during the boss raid operation, a player named Shigemura Yuuna—known in-game as Yuna—would die while trying to help players surrounded in the wilderness dungeon. Surrounded and killed by the Jailers.

Recalling the Sword Art Online storyline, Kai slowly stepped into the labyrinth entrance. A faint bluish glow shimmered on both sides of the passage, the effect of monsters spawning.

As the light faded, two monsters appeared. They looked like bipedal mountain goats, each holding a stone axe.

The moment they materialized, the two goat monsters locked eyes on the lone figure in the passage. With loud bellows, they charged forward, axes raised high.

Kai lowered his stance slightly. His right hand lifted the sword.

In the next instant, his black silhouette suddenly moved.

The ghostly blue blade gleamed with a cold, cutting edge. Swift slashes glinted in the dim light, carving deep red gashes across the monsters' bodies.

While Kai was busy dealing with the first two, another two monsters spawned behind him.

Seeing them out of the corner of his eye, Kai didn't dare be careless. With a quiet shout, his HP bar at the top-left of his vision began to drop slowly. In exchange, several crimson sword energies began to manifest around him.

Metallic shrieks echoed through the corridor as the sword energy surged.

It was still unclear how the inheritance system had managed to function in-game. Kai couldn't bring his real-world stats in, but his passive skills still worked fine. Both Ketsui no hikari and his sword aura had been quantified into usable game mechanics. In fact, the experience barely differed from reality—except he didn't have to worry about self-damage from overuse anymore. Here, taking HP loss could simply be remedied with healing potions.

He locked onto the two newly spawned monsters and whispered, "Go."

Shing shing shing—

The crimson blades sliced through the air, cutting the monsters to ribbons in a matter of seconds. Meanwhile, the two goat monsters in front of Kai were also nearing their limits.

Blocking one of their stone axes, Kai drew a half-circle with his blade, lowered his body, gripped the sword tightly with both hands, and lunged backward.

The blade pierced through something tough—like leather armor—and Kai didn't hesitate. He switched his left hand to the lead grip, opened his right hand to block against the sword guard, and twisted his waist.

Riiip—

The mountain goat monster was sliced from lower abdomen to its left flank, a deep, savage gash. Its HP bar instantly depleted. A moment later, it burst into blue particles.

Unfazed, Kai transitioned straight from that motion into a spinning slash. He twisted his body like a top, then thrust his arm forward, sweeping the blade in a crescent. A deadly chill surged from the sword as it slashed through the air toward the second monster.

Vmm—

The sword whistled, slicing clean across the monster's neck. After a few seconds of silence, the creature shattered into glowing fragments.

Kai rose, sheathing his sword. Without pause, he continued deeper into the labyrinth.

He needed to level up to maintain high stat values. Though he couldn't bring in his real stats, the passive skill bonuses from the [Black Swordsman] class—especially the four basic ones—gave him swordsmanship talent that was still extremely valuable.

Even without overwhelming attributes, this was a perfect opportunity to polish his raw sword technique. In some ways, this could even be considered a blessing in disguise.

Outside the labyrinth on Floor 39, twilight faded, and a giant moon rose into the sky. Birds flitted across the plains beneath the night, circling silently in the dark.

In the depths of the labyrinth, Kai's black silhouette blended into the shadows. Sword in hand, he marched steadily onward. Every step was accompanied by faint flashes of cold sword light, falling like silent rain.

The night was long. So was the road ahead.

October 16, 2023

The KOB (Knights of the Blood) Guild successfully located the boss room on Floor 40. The announcement caused a stir among all players.

Finding the boss room meant the start of the raid operation. If they could defeat the boss, it would mark another step forward in clearing this deadly game.

October 17

KOB carried out a recon mission against the boss and convened a strategy meeting. They finalized the operation plan and selected the raid party.

October 18, 9:00 AM

At the city of Jayreum, 48 elite players were selected from among hundreds to form an assault team, arranged into five squads. Led by KOB's leader Heathcliff and vice leader "Flash" Asuna, they vowed to defeat the Floor Boss:Bracken the Prison Warden.

A corridor crystal capable of teleporting the entire group lit up, shining even brighter than the midday sun. The glowing gate appeared, and the squads stepped in one by one.

Moments later, the light faded, and the corridor vanished. The battle group had departed.

Cheering erupted as the crowd—civilians and second- and third-rate players—applauded the brave warriors departing on their mission. Even after the last of the raiders disappeared, the applause didn't stop.

In a small alley at the end of the street, Kai bit into a fresh apple he had bought from a vendor. The crispness and taste were almost indistinguishable from real-world fruit.

His gaze, however, was fixed on a particular pair in the crowd.

The young man's ID was Nautilus. And the girl he was speaking to—

Her name was Yuna.

Crunch…

Leaning silently against the alley wall, Kai continued chewing. He didn't move otherwise. Not until he was nearly finished with his third apple did a disturbance ripple across the square.

A man staggered in from the west plaza.

"Someone... please! Help us!"

The man, clad in leather armor with a curved blade at his hip, was in bad shape.

The armor—top-tier frontliner gear—was in tatters. Worse, a black throwing spear was embedded in his back.

Several players rushed over to pull the spear out and asked what had happened.

Gasping, the man shouted:

"I—I have five companions, trapped in the wild dungeon... surrounded by a horde of mobs! They can't hold on much longer... Who will help me rescue them?!"

Whoom—

His words sent shockwaves through the crowd. A collective gasp spread through the square.

Monsters on Floor 40 were notoriously tough—especially in its dungeon, themed around "prison." That dungeon often produced lethal trap events: full lock-downs, mass monster spawns, and almost certain death.

Under the man's desperate plea, only nine stepped forward.

Two were members of the guild Wind, Forest, Fire, Mountain, who had failed to make the boss raid squad. One was Nautilus, now assigned to KOB's second team. The rest were five high-level solo players.

And lastly—

A girl dressed like a bard. A water-blue dress trimmed in gold, a white lute cradled in her left arm, a shortsword at her right hip, and a wide-brimmed hat with a single white feather.

Yuna—Shigemura Yuuna.

Eyes narrowing slightly, Kai watched as the two five-person rescue teams departed westward.

He finished his apple in silence, letting the core fall. As it dropped, it disintegrated into a soft trail of blue light.

Kai had previously bought four apples from a street vendor, and now only one remained. He casually placed it into his backpack slot, then followed the rescue team out of the district.

…

The 40th floor's wilderness was a barren land of cold, desolate rock. Jagged cliffs jutted out everywhere, breaking the terrain into scattered fragments.

The red-and-white uniform of the Knights of the Blood fluttered as they ran across the wasteland. Yuna ran at Nautilus's side, but his heart was filled with unease.

He didn't want his childhood friend to step onto a battlefield where she'd have to fight monsters to the death. Even though this was only a virtual world inside a game, if your HP hit zero, you would really die.

Just the thought of possibly losing the girl forever made the anxiety in Nautilus's chest rise to his throat, but he couldn't convince her to return to the safety zone inside the circle.

He had known Yuna since they were kids. She was the kind of person who rarely changed her mind once she decided on something—gentle on the outside, strong-willed inside.

So, if he couldn't change her mind about staying at the front lines, the only option left was to stay by her side and protect her at all costs.

His hands, tightly gripping his weapon, were trembling. Nautilus swore to himself that he would protect her no matter what.

Just then—

"We're almost there!"

The scimitar-wielding player running ahead turned back and shouted to everyone.

Following his shout, a structure resembling a half-collapsed ruin came into view.

A field dungeon…

Nautilus tensed as he stared at the part of the dungeon that jutted above ground, but remembering the girl he had vowed to protect was right beside him, it was as if new strength surged through him. It carried him forward into the dungeon.

The dungeon interior resembled the central prison area of the main city but was far more dilapidated. It was clearly a ruin. And instead of NPC jailers patrolling it, there were monsters.

On the way in, the group encountered two waves of attacks, one from slime-type monsters and another from goblin-type monsters. The rescue team easily defeated them and continued to the dungeon's core.

A large, heavy iron gate blocked the center path. Beyond it, several figures could be seen swinging their weapons, locked in battle with monsters.

Farther in, a towering two-meter-tall figure sat arrogantly on a stone chair. Behind a mask like a hockey helmet, a pair of vicious eyes stared mockingly at five struggling players being swarmed by torturer-type mobs.

There was no doubt. This was the dungeon's boss. All the other torturers were just endlessly respawning mobs. The key to clearing the dungeon was defeating this warden boss.

"That's them! They're still alive!"

Seeing their comrades still fighting, the scimitar wielder cried out and rushed up to the iron gate, peering inside anxiously.

"What do we do about this gate? There must be some kind of switch, right?"

Unlike the scimitar wielder, Nautilus calmly assessed the situation and voiced the question.

"There's a lever behind the boss. That's probably the switch. But as soon as anyone gets close, the boss moves. I barely escaped before the gate closed."

"So, if we want to support them, someone inside has to get close to the boss and pull the lever first?"

Two players from the Wind, Forest, Fire, and Mountain guild exchanged glances and shook their heads. "That's way too risky. Once the boss activates, how many people do you think can actually escape?"

The five scattered solo players nearby didn't quite understand, but Nautilus, as a member of the raiding party, did.

SAO… no, not just SAO, every MMO boss shared a trait: fighting them offensively was far easier than trying to escape.

When raiding, bosses could be interrupted, minimizing their damage. But once a boss entered full attack mode, things became uncontrollable. Trying to get everyone out could lead to even more people being trapped.

Too risky…

Frowning, Nautilus said, "Let's just defeat the boss directly."

"D-Defeat the boss?!"

The five solo players were shocked.

"But none of us have ever taken down a boss before…"

"It's fine. We have the level advantage, and three of us are from the raiding team. As long as we're careful not to get swarmed, we can beat the Warden."

Dressed in the red-and-white uniform of the KOB guild, Nautilus's words carried weight. The hesitant players began to steady their nerves.

"So, how do we get them close to the boss?"

Having agreed on a strategy, the shorter of the two Wind, Forest, Fire, and Mountain players pointed to the five nearly exhausted fighters behind the gate. "In their current state, they can't even handle the small mobs, let alone approach the boss to pull the lever."

"Hmm…"

Everyone exchanged worried looks. No one had a good solution.

At that moment, Yuna, who had been quietly observing, walked to the gate. She cupped her hands around her mouth and took a deep breath.

"Hey! You guys inside—can you hear me? If you can, come a little closer. I can help you!"

Though confused, the five trapped players began moving toward the gate while still fending off the torturers.

Seconds later, they reached the gate. Seeing how badly off they looked, Yuna began to play her lute. A powerful melody filled the air, echoing throughout the prison.

"…Huh?"

Hearing the song, the five fighters were startled at first. But then, as strength surged through them, their eyes lit up. Their movements became smoother and more precise.

After 30 seconds of music, the lute rang out a final chord. At the same time, a bright yellow icon appeared beneath every player's HP bar.

The HP of the five injured players inside the gate began to steadily recover.

"Woohooo!!"

Feeling the fatigue and pain melt away, the once-hopeless players shouted in relief.

Yuna smiled. "The Heal over Time effect will last a bit. Hurry and finish off the small mobs, then pull the lever."

"Got it!"

Nodding vigorously, the five charged the torturers and cleared them, then ran toward the boss, their eyes full of determination.

Seeing the players approach, the Warden Boss rose from his chair, let out a roar, and swung his massive steel axe.

But boosted by Yuna's song, the five showed no fear. Four of them drew the boss away while one ran to the lever and pulled it.

Clang! Clang!

The iron gate screeched as it began rising.

"We did it!"

The scimitar wielder punched the air in joy and dashed through the half-open gate.

The Wind, Forest, Fire, and Mountain duo shook their heads with a smile but understood his urgency to rescue his comrades.

"Let's go."

Nautilus glanced at the others, drew his sword, and charged in with the rest.

Nine high-level players, including three from the raiding team, along with the five rescued ones—fourteen in total—were more than enough to handle five torturers and one Warden Boss.

In just five minutes, the boss was clearly overwhelmed. Its HP was in the yellow zone.

"Almost there! Keep going!"

As the lead attacker, Nautilus judged that the boss had no more tricks left. He raised his voice. "Focus! Let's finish this!"

But at that moment—

Screeeeeech!

The sound of metal grinding drowned out his shout, echoing from the walls around the prison.

One after another, hatches opened, revealing pitch-black tunnels filled with swarming torturer mobs—enough to bury everyone.

A trap…

"Prepare the crystals! It's a trap!"

As soon as he understood what was happening, Nautilus shouted. But the next instant, a heavy blow smashed into him, knocking the breath from his lungs.

While he had taken his eyes off the boss, it had spun with its axe and struck everyone in range.

"Urgh—!"

Nautilus hit the ground hard, rolling a few times before landing at Yuna's feet.

The sudden reversal shocked him. But Yuna, who had been watching silently, immediately grasped the situation.

"Yu…"

"Eiji, please… Defeat the boss. Save everyone."

Yuna turned away from Nautilus's trembling eyes. She raised her lute and sang again.

This time, her voice was even stronger, like sunlight turned into sound.

But no buff appeared on anyone. That was expected. This song didn't heal—it increased aggro.

As the song echoed, all monsters—torturers and boss alike—stopped and turned toward the little girl singing.

Yes… this is what I wanted.

Seeing the effect, Yuna smiled. She kept playing as she ran away from the group.

"Yuna——————!"

Nautilus's desperate voice echoed behind her. Yuna paused mid-stride.

I guess I'll never see Eiji again… That makes me a little sad.

But Eiji is timid and hates being alone, so he'll probably be even more miserable than me.

Sorry, Eiji… I won't be there to cheer you on anymore.

She stopped playing and looked back. Through layers of monsters, she could almost see Eiji's tear-filled face.

Ahh… he's crying, isn't he? That's so like him.

If you're sad, just eat this and cheer up.

She pulled out a jar of rainbow-colored candies from her inventory and hurled it toward Nautilus.

Eiji will be okay…

The jar arced through the air—

And smashed into a black figure rushing in from afar.

Crash!

A blue sword flashed. The blade cleaved through the flying "projectile," sending a rain of candy scattering.

Everyone stared at the newcomer.

Kai didn't slow down. Blue energy surged from his blade as he crossed dozens of meters in an instant and slashed the boss from behind.

His sword sank a third into the Warden's back, carving all the way down as the boss's HP drained visibly.

"Drsaaa!!!"

The Warden howled and burst into light, disappearing.

"He's dead?!"

Everyone was stunned. Not just the solo players, but even Nautilus and the others.

Kai sheathed his sword and started killing the remaining mobs. His speed was like a whirlwind, clearing them in seconds.

When the last monster died, Kai walked up to the stunned Yuna, opening his system window.

"Sorry about that. I kinda broke your candy jar…"

He pulled out the last apple from his backpack. "If you don't mind, let this be my apology."