Walking along the dimly lit mountain path, Kokushibo made no effort to conceal his appearance. Maintaining a controlled human guise for extended periods was unnecessarily taxing even for him.
Suppressing one's true nature, dulling one's senses, restraining instinct… it was akin to forcing the body into constant discomfort.
Who would willingly constrict their perception every waking moment?
Beneath the pale glow of the moon, Kokushibo moved silently, his steps steady. His breathing felt unusually smooth, each inhalation flowing with effortless rhythm.
"…Perhaps this is the influence of Moon Breathing."
Of course, the thought was fleeting.
In truth, it was far less mystical he had simply spent the entire day confined within a basement, and the open night air now felt refreshing by contrast.
As he continued forward, however, a subtle unease crept into his mind.
This path should have led back to his residence.
Yet, the surroundings felt… unfamiliar.
The terrain shifted in ways he did not recall, the landmarks subtly distorted. For a moment, he wondered if prolonged confinement had dulled even his sense of direction.
Just as he slowed, reconsidering his route, a powerful presence brushed against his perception.
A moment later
Flames surged into the night, their glow tearing through the darkness.
Kokushibo did not need to guess.
"…So, it is him again."
It had been over a year since his last encounter with Rengoku Shinjuro, the former Flame Hashira.
Despite standing on opposing sides, Kokushibo found their previous exchange… unexpectedly engaging.
Curiosity stirred.
He altered his course and approached.
From a distance, the scene unfolded clearly.
Several demons had been cornered, their movements frantic under the relentless assault of Demon Slayers. The swordsmen clearly inexperienced struggled to maintain formation, their breathing uneven, their strikes lacking precision.
At the edge of the battlefield stood Shinjuro.
He did not intervene.
Arms folded, gaze sharp, he observed in silence.
This was training.
A crucible meant to temper resolve.
Only in the face of real danger could courage take root. Unless a life-threatening situation arose, he would not step forward.
Kokushibo watched from the shadows, his presence concealed.
These demons were insignificant far beneath the rank of the Twelve Kizuki.
There was no reason for him to interfere.
After a short while, boredom set in.
He turned to leave.
But that single motion did not escape Shinjuro's notice.
"Who's there?!"
In an instant, the former Hashira's presence sharpened. His hand moved to his sword, and he surged forward.
Kokushibo clicked his tongue inwardly and pivoted away.
Troublesome.
But Shinjuro was not one to ignore suspicion.
His grip tightened.
His breathing changed.
Flame Breathing, First Form: Unknowing Fire!
With explosive speed, Shinjuro closed the distance, his blade trailing a blazing arc as it cut through the night.
Kokushibo exhaled softly.
Escape would only draw more attention.
In one smooth motion, he drew his katana.
At the same time, he ensured his additional eyes remained hidden beneath the shadow of his hair.
Steel met steel.
A single, precise movement
He deflected the attack.
The clash rang out sharply, the force dispersing into the surrounding air.
Shinjuro landed, his eyes widening slightly.
"…You."
Recognition followed quickly.
"Iwakatsu… is that truly you?"
During their previous meeting, Kokushibo had introduced himself only by that name abandoning the surname Tsugikuni Clan entirely.
The truth of his identity had long since faded from common knowledge.
For centuries, Kokushibo had remained within the shadows, rarely stepping into the human world.
Shinjuro's expression shifted not to suspicion, but to excitement.
"You blocked that strike… with pure swordsmanship!"
His voice carried genuine admiration.
"To think someone could deflect Flame Breathing so cleanly…!"
A grin spread across his face.
"Join the Demon Slayer Corps!"
Kokushibo paused.
…What?
For a brief moment, even he was taken aback.
Recruiting him?
From under Muzan's very command?
"…You would have me hunt demons," Kokushibo said dryly, "while I cannot even see?"
He gave a faint, self-deprecating chuckle.
"That strike was instinct alone. I merely reacted to your killing intent."
Shinjuro froze then slapped his forehead with a loud laugh.
"Ah! Right your eyes!"
The booming voice, the fiery temperament… it was unmistakable.
Kokushibo found himself momentarily reminded of Kyojuro Rengoku.
The resemblance was undeniable.
"I wandered here by chance," Kokushibo continued calmly. "What is happening? I heard screams."
If he was to maintain the guise of blindness, it had to be flawless.
Shinjuro waved it off, placing a firm hand on his shoulder.
"Nothing to worry about! Just demon extermination."
Behind them, the battle had already concluded.
The demons were slain.
Shortly after, members of the Demon Slayer Corps' support unit the Kakushi emerged to handle the aftermath.
Without further hesitation, Shinjuro turned back.
"Come. You should rest."
Before Kokushibo could respond, his arm was seized, and he was pulled along.
At the Rengoku residence, Kokushibo knelt upon the tatami, a cup of tea placed before him.
He had briefly entertained the possibility that he might uncover something about the Demon Slayer Corps' inner workings.
Instead
This was simply Shinjuro's home.
Entirely ordinary.
Shinjuro was not a man of refinement. The tea was plain, lacking any particular quality.
Kokushibo did not mind.
As long as it contained no trace of wisteria, it was acceptable.
(And in truth, such concern was unnecessary wisteria was rarely used in such a manner outside of demon deterrents and poisons.)
A faint sound broke the silence.
Coughing.
It echoed softly from another room.
Kokushibo tilted his head slightly, as though listening.
"Someone is unwell."
Shinjuro's expression changed.
For the first time, the fiery confidence wavered.
"Yes… my wife."
His voice lowered.
"She has always been frail. Since the birth of our youngest son, her condition has only worsened."
Kokushibo considered this.
A Hashira's household would not lack resources.
If money could not resolve it, then the illness was likely rare… or beyond conventional treatment.
"…A persistent illness that even physicians cannot cure?"
Shinjuro nodded grimly.
In that moment, a thought surfaced in Kokushibo's mind.
"…I know someone."
Shinjuro looked up instantly.
"A doctor. Her skill surpasses that of ordinary medicine."
Hope ignited in his eyes.
"I will pay anything!"
Kokushibo shook his head.
"She has no interest in money. Her family was slaughtered by demons."
He paused deliberately.
"But if she learns you are part of the Demon Slayer Corps… she may agree to help."
The name of Tamayo lingered unspoken, yet implied.
Shinjuro stepped forward, gripping Kokushibo's hands tightly in his excitement.
"Then please introduce me!"
Realizing his outburst, he quickly released him.
"…Forgive me. I lost myself for a moment."
His gaze steadied.
"Iwakatsu… how can I repay you?"