Kokushibo very nearly struck him dead on the spot.
Pathetic.
The sheer spinelessness before him was almost offensive.
Yet, after a moment's consideration, he restrained himself. If this man were turned into a demon, it would defeat the purpose entirely. A creature bound to the night could never fulfill tasks that required moving freely among humans.
His thoughts halted briefly as the shallow cut on his palm closed, the blood retracting unnaturally back into his flesh.
…So that was it?
He had gone through the trouble for nothing?
Without hesitation, Kokushibo seized the man's trembling hand and sliced across his palm once more. Fresh blood welled up instantly.
"Speak," Kokushibo said coldly, his voice carrying quiet menace. "Before that blood dries… what do you intend to do?"
Watanabe Kihei was on the verge of collapse, tears streaming uncontrollably.
What could he possibly do?
Yet, under the suffocating weight of death's shadow, desperation forced clarity upon him.
"S-Sir! Then… turn my secretary into a demon! Let him protect me and supervise me as well!"
The words spilled out in a frantic rush.
Even he seemed shocked at his own suggestion.
Kokushibo regarded him with a flat, unreadable gaze.
"…Does this secretary have family?"
"N-No! Just like me an orphan! No relatives at all!"
Kokushibo exhaled faintly.
…Fitting.
"Bring him."
Moments later, the secretary was ushered into the room.
A young man composed, though clearly unsettled by the tension.
His name was Saito Arashi.
Before he could fully comprehend what was happening, Kokushibo stepped forward.
There was no ceremony.
No hesitation.
A single motion
Blood was given.
Transformation began.
Unlike ordinary demons, those created through Kokushibo did not fall directly under the absolute command of Muzan Kibutsuji.
This anomaly stemmed from Kokushibo's unique standing and the depth of Muzan's trust in him.
However, Kokushibo himself had never cared to gather followers. Strength alone had always been sufficient.
Until now.
As the transformation completed, Saito Arashi fell to one knee, instinctively bowing.
"From this moment," Kokushibo said, his tone calm yet absolute, "you will protect this man. You will also act as my intermediary."
"Yes… sir."
"Do not kill indiscriminately," Kokushibo added, his gaze sharpening slightly. "If you draw the attention of the Demon Slayer Corps, I will personally end you."
Saito lowered his head further.
"I understand."
With matters settled, Kokushibo prepared to leave.
Kihei, eager to prove his usefulness, arranged a carriage for him.
The interior was sealed tightly, blocking all traces of sunlight.
Even so, Kokushibo instructed the driver to halt before dawn and resume travel only at night.
The driver, though puzzled, did not question him.
Generous payment erased most doubts.
By the following evening, Kokushibo arrived at the hidden residence of Tamayo.
Curiously, neither she nor Yushiro had gone out that night.
After dismissing the driver with a warning and additional payment to ensure silence Kokushibo entered the house.
Silently.
Utterly without presence.
His breathing stilled.
His aura vanished.
Such was his control that even a being like Muzan might not notice him immediately if caught off guard.
Within the house, Tamayo and Yushiro remained unaware.
"…Lady Tamayo," Yushiro said, his voice tense, "are you truly going to assist that Upper Rank?"
His disdain was evident.
Tamayo sighed softly.
"Whether we comply or not… we cannot oppose him directly."
Yushiro clenched his fists.
"Then we should prepare something stronger an antidote that could turn him human again!"
Tamayo's expression grew more complicated.
"…He is still the elder brother of Yoriichi Tsugikuni. I cannot allow him to be destroyed alongside Muzan."
Behind the door
Kokushibo's eyes opened.
A faint killing intent flickered.
So.
This was their plan.
The door burst open.
Wood splintered under the force.
Kokushibo stepped inside without restraint.
Yushiro reacted instantly, moving to shield Tamayo.
"You what are you doing here?!"
His voice lacked conviction.
Kokushibo did not answer.
He moved.
In a single motion, he struck Yushiro aside, sending him crashing across the room. Before Tamayo could react, Kokushibo's hand closed around her throat, lifting her slightly.
"Have you forgotten," he said quietly, "what I warned you?"
His six eyes gleamed, overwhelming in their intensity.
Tamayo struggled, yet her voice remained steady.
"Walking this path will only bring more suffering… You should abandon it."
She met his gaze.
"…Yoriichi Tsugikuni would not wish to see you like this."
A flicker
Something sharp passed through Kokushibo's expression.
Behind him, Yushiro rose again, charging forward recklessly.
"Release Lady Tamayo!"
He possessed no refined techniques only the brute strength and regeneration of a demon.
It was meaningless.
Without even turning, Kokushibo drew his blade.
A single swing.
Clean.
Precise.
Yushiro's limbs were severed instantly, his body collapsing as regeneration struggled to keep pace.
Kokushibo lowered his sword.
He had held back.
Killing him would serve no purpose.
Releasing Tamayo, he spoke again.
"Prepare your things. You will come with me."
Tamayo dropped to her knees, coughing violently, steadying herself as she regained breath.
"…Is it a demon?" she asked.
Her concern was genuine.
Kokushibo let out a short, dismissive breath.
"A human."
He seated himself calmly.
"The wife of the Flame Hashira Ruka Rengoku."
Tamayo froze.
Of all possibilities… this was not one she had expected.
"You intend for me to treat a human?" she asked slowly. "A member of the Demon Slayer Corps' family?"
Her gaze sharpened.
"…Does Muzan know?"
"No."
The answer came immediately.
Clear.
Unambiguous.
Kokushibo continued,
"The Flame Hashira, Rengoku Shinjuro, has accepted me. His son is now under my protection. In exchange, he will teach me Flame Breathing."
Tamayo fell silent.
The situation was… unprecedented.
Yushiro, now partially regenerated, hurried to her side.
She lowered her gaze, thoughts in turmoil.
Kokushibo had shown trust.
Yet she had been considering how to destroy him.
…
Kokushibo's patience wore thin.
"Enough. Prepare."
Yushiro immediately protested.
"Have you lost your mind?! That is a Hashira's household!"
Kokushibo rose and stepped forward.
His blade came to rest lightly against Tamayo's neck.
"Go," he said quietly, "or I deliver you to Muzan Kibutsuji."
Silence.
Then
"…I will go," Tamayo said.
Yushiro froze.
Ignoring his protests, she stood and followed Kokushibo.
After a brief hesitation, Yushiro followed as well.
The journey took two days.
As dawn approached each morning, Kokushibo secured lodging, ensuring they remained hidden from sunlight.
When night fell again, they resumed travel.
Inside one such inn, Yushiro paced restlessly.
"This is madness," he muttered. "Entering a Hashira's home… we will be killed the moment we are discovered!"
He turned urgently to Tamayo.
"Lady Tamayo, let us escape! I will hold him off you must flee!"
Tamayo smiled faintly.
"No."
Her voice was calm, unwavering.
"I have chosen to trust him."
She reached out, gently taking Yushiro's hand.
"Say no more."
Yushiro froze.
His face flushed instantly.
And for a brief moment
Even in the shadow of danger
Silence settled between them.