Tanjiro's father had died, leaving him as the sole heir to the Kamado bloodline. The weight of generations weighed on his shoulders like mountain snow threatening to avalanche.
He and Eri had just begun to build their life together, a simple existence filled with the quiet rhythms of mountain life. The scent of pine and wood smoke clung to their modest home, mingling with the earthy scent of wild vegetables growing in carefully tended patches around their dwelling.
The breathing technique Tanjiro practiced had been refined through his father's painstaking research, built upon the accumulated wisdom of countless elders who had come before. Each generation had added its own understanding, its own refinements to the ancient art that flowed through the Kamado blood like a sacred river.
His father had passed this knowledge on to him with trembling hands and urgent whispers, knowing the terrible price that such devotion demanded. The price for pushing the limits of Sunbreathing had always been the same - shortened lifespans, bodies burned out by the very power that made them strong.
Beginning with Tanjiro's generation, however, something fundamental had changed. The hidden dangers that had plagued the Sun Breathing lineage for centuries had finally been resolved through generations of careful study and sacrifice. His father's final gift was a technique so refined that it no longer devoured its practitioners from within.
For the first time in the history of the Kamado Clan, their descendants could expect to live normal lives while wielding the power of the sun itself.
Oboro had settled into a comfortable routine at the foot of Mount Kumotori, living the quiet life of a retired gentleman in the bustling city below. His modest home sat among streets buzzing with the energy of a community finding its footing in a rapidly changing world.
Every few weeks, Tanjiro made the trek down the mountain trails, carrying bundles of carefully split firewood or baskets of wild vegetables to sell at the market. The extra income helped support his growing family, and the trips allowed him to purchase necessities that could not be gathered or produced on the mountain.
Each trip always included a visit to Oboro's residence.
The routine had become as natural as breathing. Tanjiro would finish his business in the city and then make his way to the quiet street where Oboro lived. Though he knew the former Demon Slayer had no material needs, Tanjiro always brought gifts - special wild vegetables he'd discovered in hidden mountain groves, or carefully preserved mountain delicacies that could not be found anywhere else.
The most precious of these gifts were the blue spider lilies.
After several generations of dedicated cultivation and study, the current Tanjiro had mastered the art of keeping these rare flowers "fresh" far beyond their natural lifespan. What had once been a fleeting blossom that withered within hours could now be preserved for days, even weeks, through techniques passed down and refined through the family line.
The skill had its origins in an old family story about Oboro's fondness for wild vegetable soup during his previous visits to the mountain. This preference, along with the knowledge of how to prepare such dishes, had been carefully preserved through oral tradition. Each generation had added its own discoveries, its own improvements to the recipes that could coax flavor and nourishment from the mountain's bounty.
The blue spider lilies Tanjiro had brought were different from the ones Oboro had encountered on Mount Kumotori a century ago, during that fateful winter. According to Tanjiro's patient explanations, they were related species within the same botanical family, with similar medicinal properties, but adapted to different seasons and growing conditions.
The summer variety lacked the potent effects and exquisite flavor of its winter cousin, but it was far more accessible. The harsh growing conditions remained the same-these flowers required precise combinations of soil, moisture, temperature, and spiritual energy that made them incredibly rare even under the best of circumstances.
The Winter Blue Spider Lily was first discovered by Kamado Tanjuro's wife in her desperate search for medicine to treat her husband's deteriorating condition. She had experimented with countless mountain plants, grinding them into powders and brewing them into soups, hoping to find something that would ease his suffering.
The winter variety had proven far superior to any other remedy, but in recent years, the precious blossoms had become increasingly difficult to find. What had once been rare was now approaching impossibility.
Oboro understood the true reason for this scarcity. The will of the Demon Slayer World itself manipulated the natural order, deliberately weakening the effects of the Blue Spider Lily to maintain a certain cosmic balance. As the world's power systems evolved and strengthened, certain benefits had to be curtailed to prevent complete disruption of the established order.
Aside from flowers, Tanjiro often brought hand-carved wooden objects as gifts. He had noticed the walking stick Oboro carried - a piece made by one of his ancestors generations ago, worn smooth by countless miles of mountain and forest paths.
Despite Oboro's careful preservation, time had left its mark on the ancient wood. Tiny cracks spidered across its surface, and deep gaps had opened where moisture and temperature changes had taken their inevitable toll. The staff that had once been strong enough to support a warrior's weight now seemed fragile, almost delicate.
With characteristic thoughtfulness, Tanjiro had carved a replacement. The new staff was made of mountain oak that had weathered decades of harsh winters, its grain tight and strong. He had shaped it to the dimensions of the original while adding subtle improvements-better balance, a more comfortable grip, decorative elements that honored the Kamado clan's artistic traditions.
It was a gift that spoke to the deep respect and affection that had grown between them, transcending the boundaries that should have separated man from demon.
As weeks turned into months, the situation beyond Mount Kumotori began to deteriorate rapidly.
The number of demons throughout the land had exploded exponentially, but the source of this plague wasn't Muzan, as everyone might have expected. Instead, the responsibility lay with Doma and Kokushibo, the two Upper Moons who had vanished into the shadows after their encounter with Oboro.
Both demons remained significantly weaker than Muzan in raw power, which meant they had to be extremely careful about revealing their location. The Demon King's hunt would be relentless and merciless if he discovered their rebellion. To survive, they needed to create enough chaos and confusion to keep Muzan constantly distracted.
The most effective distraction was the Demon Slayer Corps, whose members could occupy Muzan's attention for long periods of time. By creating new demons and strategically unleashing them, Doma and Kokushibo could ensure that the Demon King would be too busy fighting fires to hunt down his former subordinates.
Meanwhile, Muzan continued his desperate quest to understand Soul Force, hunting down the remaining heirs with single-minded determination. Oboro's revelation of his ultimate destiny had ignited a fire of urgency within him that burned brighter with each passing day.
Unfortunately for the demon king, his previous aggressive tactics had backfired spectacularly. The surviving Inheritors had learned the patterns of his hunts, and many had gone into hiding or made elaborate contingency plans. Some had formed alliances with each other, creating networks of mutual protection that made them far more difficult to eliminate.
Muzan's grand strategy was crumbling, and there was nothing he could do to stop it.
All of these dramatic developments unfolded without Oboro's direct involvement. He simply remained in his comfortable home, quietly observing the direction this world was taking by means both mundane and supernatural. Like a chess master who had already calculated the endgame, all he had to do was wait for the pieces to move into their inevitable positions.
As time passed, the consequences of his long laid plans began to manifest themselves in ways both subtle and dramatic.
Doma's Eternal Paradise had emerged in an entirely new form, its previous incarnation having been utterly destroyed during Muzan's vengeful rampage. The ice demon had learned from this defeat, abandoning the strategy of maintaining a fixed base in favor of something far more dangerous.
Now calling himself a chosen emissary of God, Doma had begun to spread his influence through religious evangelism. He traveled constantly, never staying in one place long enough for Muzan to track him down, but leaving behind networks of devoted followers wherever he went.
Most shocking of all, many demons who had originally served under Muzan's command had begun to defect to join Doma's growing movement. The ice demon had learned to manipulate both the fear and resentment other demons felt toward their tyrannical king, offering them something Muzan never had - freedom from the blood curse that bound them to his will.
This development proved that Doma had indeed mastered fundamental aspects of spirit power. His enhanced spiritual abilities, combined with the demonic essence he had absorbed from Oboro's blood, had elevated him to a level where he could challenge Muzan's absolute dominion over the demonkind.
The implications were staggering. For the first time in over a thousand years, the demons had a choice as to whom they would serve.
The structure of the Twelve Demon Moons had also undergone massive upheaval. New faces had appeared in both the upper and lower ranks, many of them completely unknown to the Demon Slayer Corps' intelligence networks. But before these new recruits could establish themselves or pose a significant threat, they had been systematically eliminated by an unknown assailant.
The methodical nature of these assassinations left little doubt as to the identity of the perpetrator - only Kokushibo possessed both the skill and intimate knowledge necessary to dismantle Muzan's organization so efficiently. As a former Upper Moon One, he understood every aspect of how the Twelve Demon Moons operated, from their recruitment methods to their communication protocols.
Each elimination was a carefully calculated blow to Muzan's prestige and power base, designed to demonstrate that the Demon King was no longer invincible.
At the same time, the Inheritors had begun their own campaign of demon creation, taking advantage of Muzan's distraction to rebuild their strength. The basic human desires for power and immortality made their recruiting efforts surprisingly easy - even people who understood the terrible cost of becoming a demon would often choose transformation over death when faced with terminal illness or desperate circumstances.
Doma had recognized this psychological vulnerability and deliberately exploited it on a massive scale. Rather than hide the darker aspects of human nature, he magnified them, using people's fears and ambitions to create willing converts to his cause.
Unlike Muzan, who used fear and the threat of instant death to maintain strict control over his subordinates, Doma was remarkably generous with his power. He understood that demons grew stronger by devouring each other, and he actively encouraged this behavior among his followers. In his twisted logic, quantity would eventually produce quality-given enough demons competing for strength, some would inevitably transcend their original limitations and attain something approaching godhood.
This strategy was already bearing fruit. Several of the newer demons were displaying rudimentary spiritual abilities, touching the edges of the soul power that had previously been Muzan's exclusive domain.
Adding to the chaos was Gyutaro, whose rampage across the land had earned him a reputation as an unbridled force of destruction. The former Upper Moon Six, accompanied by his sister Daki, had become something of a natural disaster - appearing without warning to fight anyone and everyone who crossed their path.
They had killed the Hashira Demon Slayer Corps, eliminated the Heirs, destroyed newly appointed Upper Moons, and even managed to hold their own against both Doma and Kokushibo in brief encounters. Their complete lack of allegiance to any faction made them uniquely dangerous, as no one could predict where they would strike next.
For Gyutaro, this endless conflict was simply the fulfillment of his original mission. Oboro had charged him with eliminating all of the Upper Moons, and he had made considerable progress toward that goal. Gyokko and Hantengu were dead at his hands, while Akaza had been devoured in a particularly brutal battle-though the exact circumstances of that death remained unclear.
Only Doma and Kokushibo remained on his target list. As long as those two existed, his mission would remain incomplete, driving him to seek them out no matter how many other enemies he had to fight through.
Muzan had tried to eliminate Gyutaro several times, recognizing the threat he posed to the established order. But by the time of these confrontations, Gyutaro had already consumed the power of several Upper Moons, making him far stronger than he had been during his original reign. When the battle turned against him, he simply fled rather than fight to the death, his enhanced abilities making him nearly impossible to catch if he didn't want to be found.
The Demon King's frustration with the situation reached dangerous levels. His teeth gritted as he thought of the scarred demon who seemed to mock his authority with every breath.
The web of enemies surrounding Muzan had grown to include virtually every major power in the land. Aside from obvious threats like the Demon Slayer Corps, he now faced coordinated opposition from Doma's religious movement, Kokushibo's strategic assassinations, Gyutaro's indiscriminate violence, and the surviving heirs who blamed him for centuries of persecution.
For the first time since his transformation into the Demon King, Muzan found himself truly outnumbered and outmaneuvered. The careful balance of terror that had sustained his reign was crumbling, and each day brought new challenges that tested the limits of his power.
Meanwhile, the Demon Slayer Corps had not been idle during this period of escalating chaos. With official government backing, they had access to resources and support networks unimaginable during their previous underground existence. The scope of their operations was rapidly expanding, and the quality of their training had improved dramatically.
The Ubuyashiki clan had made the strategic decision to share their breathing techniques and basic training methods with the regular military forces. Veteran instructors who had spent decades perfecting their skills were reassigned to develop standardized curricula for government-sponsored demon-hunting units.
This transfer of knowledge served several purposes. It created a larger pool of capable fighters to deal with the exploding demon population, while also ensuring that the Corps' traditional techniques would survive even if its main organization were somehow destroyed.
Doma's proliferation of soul power techniques meant that Muzan was no longer unique in his spiritual abilities, eliminating one of his key advantages over both demons and humans. The playing field became more level with each passing month.
Gyutaro's constant battles against various factions had inadvertently served as a kind of advertisement for his fighting techniques. Observers from various factions had begun to study his methods, reverse-engineering his approach to hand-to-hand combat and weapon use. These findings were incorporated into training programs across the country.
Most importantly, the increased external pressure was forcing rapid advancements in breathing techniques, both among the Demon Slayer Corps and among ordinary humans who found themselves facing supernatural threats. Necessity proved to be an excellent teacher, driving innovation and refinement at an unprecedented rate.
In this environment of constant conflict and adaptation, several familiar figures had begun to emerge from the ranks of the Corps' most promising members. Names that would eventually become legendary began to appear in training reports and mission summaries.
Urokodaki Sakonji, whose mastery of Water Breathing approached true artistry. Giyu Tomioka, whose Thunder Breathing techniques crackled with barely contained lightning. These men and others like them represented the next generation of warriors who would shape the future of human-demon relations.
The stage was being set for conflicts that would determine not only the fate of individual warriors, but the nature of the world itself. Power flowed in new directions, loyalties shifted like sand, and old certainties crumbled under the weight of unprecedented change.
From his quiet home at the foot of Mount Kumotori, Oboro watched it all unfold with the satisfaction of a gardener whose seeds had finally begun to sprout. The harvest he had tended for over a century was almost ready to be reaped.
Soon, very soon, the fruits of his labor would be fully ripe.