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Kokushibo couldn't remember the faces of the people he had once loved.
He remembered his life as a human perfectly. Kokushibo knew that he had a wife and children, that he had grown up in a wealthy family, and he also remembered his dreams that he had shattered in hatred.
Yet Kokushibo had no memory of his parents' faces nor the family he had abandoned; the only face that remained imprinted in his mind as a warning of what he would never be was that of his twin brother.
As the decades passed, the demon had learned to keep at bay the angry feelings that animated him every time he thought of Yoriichi. Kokushibo, on the other hand, had defeated death by becoming a demon. He had become stronger than any other samurai or Demon Slayer.
As an Upper Moon, he had achieved perfection, which, as a price, had demanded a mask of coldness and control. Created to conceal the feelings that made him weaker and more vulnerable.
But as much as Kokushibo wanted to deny and hide it, there were moments when his armor faltered, allowing unexpected images of his past to emerge. Perfumes that he believed were now lost in the mists that had enveloped his previous life sounds that danced in his ears like ancient poems... but the faces never.
Those never surfaced in his mind until his eyes fell on a young Demon Slayer fighting tooth and nail to survive against a demon and his comrade.
His fiery blonde hair with red tips and his gaze full of passion and courage took Kokushibo's mind back to centuries before.
A similar face began to take shape, and an unexpected smile appeared on that still undefined face.
«Michikatsu-sama!»
The warm voice crept into his ears, and a shiver ran through him from head to toe.
“Who are you? Why did I forget you?” the Upper Moon asked his memories, trying to concentrate and clarify that image, but the man's facial features from his past continued to appear vague and blurry. Only his wide and happy smile seemed as bright as sunlight - an ironic thought for a demon, Kokushibo allowed himself.
Irritation began to emerge in his soul, a frustration that he hadn't felt for a long time but was equally new.
He still secretly observed the Demon Slayer, and only the desperate and cowardly exclamation of the young man's companion allowed Kokushibo to open a small window in his mind.
«Rengoku-san, we must retreat!»
Rengoku .
He knew that last name. Kokushibo had once been a comrade-in-arms of someone called Rengoku , but once again, that man's face failed to take shape in his memories, and Yoriichi's familiar voice seemed to want to whisper something in his ear.
“Was it really worth it?”
Kokushibo chased away that voice, clenching his fists tightly until he felt the nails penetrate his flesh. He sensed no pain, and the wound healed quickly without leaving a trace on his spotless skin.
«Never! I will fight until dawn if necessary!»
A sharp refusal erupted from Rengoku 's lips, and his voice mixed with that of his memories.
Different and yet now so similar.
Attack after attack, the Demon Slayer used all his energy and skills to defeat his opponent. The demon had a repulsive appearance, at least two and a half meters tall and with a powerful build. However, his skills had put the Demon Slayers in difficulty.
An acidic smoke emitted from his skin, making close combat difficult. Just touching the mist caused burn-like wounds that seemed to numb the limbs.
Rengoku, however, didn't want to give up; he continued to fight despite his wounds, and Kokushibo knew inside himself that he would win.
Even when Rengoku 's companion fell to the ground, losing consciousness, Kokushibo's certainty regarding the Demon Slayer's abilities didn’t waver.
He wasn't sure he knew where that confidence came from, and when Rengoku cut off his opponent's head, Kokushibo couldn't help but realize that he had begun to superimpose his memory onto the body of the young man in front of him.
The two images didn't match, but the Demon Slayer's face was the closest thing to something he felt was important from his past.
The Upper Moon didn't understand its meaning, but it attracted him. Kokushibo wanted to know and find out who Rengoku was.
He emerged from the shadows, finally showing himself to the Demon Slayer.
Rengoku reeled from his imposing presence but didn’t retreat. He gripped the hilt of his katana with both hands, placing himself between Kokushibo and his unconscious companion.
He was hurt and tired, yet he didn't want to show signs of weakness.
Kokushibo still observed him without speaking, trying to clarify his feelings and that serious face. His memories continued to overlap on the body of the Demon Slayer, and a smile seemed to appear on his lips, tightened in a nervous grimace of the young man in front of him.
«In my opinion, the one who cultivates it and trains hard to achieve his goals is more talented than someone born already blessed by the Gods!»
That voice again crept into the demon’s ears, and an abnormal heat spread throughout his body, radiating from his chest to his fingertips.
Rengoku attacked him. A desperate and foolish choice, but the only one for someone who had fought so bravely up until that moment.
Escape wasn’t a valid option.
Kokushibo dodged the attack and drew his katana, crossing it with Rengoku 's. A sense of familiarity added to the sensations already coursing through his limbs, and his frustration led him to fight back.
The Demon Slayer barely blocked his first lunge but didn't step back, trying to regain his balance. The Upper Moon, however, gave him almost no time to compose himself, and even without using his Breathing Style, he continued to cross his sword against Rengoku's.
«You are formidable to me, Michikatsu-sama!»
The cheerful voice in his mind joined the grunts and moans of his opponent, who stubbornly continued to defend himself with all his strength.
The heat on his chest seemed to increase, and Kokushibo couldn't help but wonder: “Who were you to me?”
Those feelings were strange. They shouldn’t and couldn’t exist, and even if they were real, why had he forgotten them?
Another attack and Rengoku 's katana was thrown a few meters away. The Demon Slayer's back crashed into the wall of a house, and Kokushibo's hand tightened around the young man's jaw.
The demon blocked it with his body, ignoring the kicks and punches Rengoku was trying to throw at him in his desperate attempt to survive.
If only he had tightened his grip a little more, he would have killed him.
“Humans are so fragile,” the Upper Moon thought, disgusted by the human race, unable to understand the power that resided in demonic blood.
However, the instinct to close his fist around Rengoku 's jaw didn’t arrive because Kokushibo's eyes had once again been captured by the young man's lips.
They moved to shout insults at him. The Demon Slayer gnashed his teeth and continued to rant at him, but the Upper Moon neither heard nor saw any of this.
The demon saw blurry outlines and soft, smiling lips ... he saw them half open and become inviting .
Before he knew it, Kokushibo had taken possession of that mouth that was screaming blasphemies and threats at him, and he had felt a shiver run over him as if Muzan had just given him more of his blood.
The familiarity of that gesture confused the Upper Moon, and with his eyes closed, he focused on the sensations he was feeling; he pushed his tongue inside the Demon Slayer's mouth, savoring that flavor, which unfortunately brought nothing back to his memory.
Kokushibo moved away before Rengoku could try to bite him and searched his face again for confirmation and memories.
That wasn't his Rengoku . The demon was fully aware of it. However, what led him to seek the Demon Slayer's mouth again was that he had called him 'his'.
The Upper Moon kissed him more passionately, chasing that memory that was taking sharper and clearer forms.
Kokushibo gripped Rengoku's jaw more firmly to prevent him from biting and pushed a knee between his legs, which was definitively blocking him. He ignored the young man's hands that had tightened around his hair in an attempt to push him away and pretended not to hear the muffled moans and groans the Demon Slayer was making.
Once, Kokushibo remembered that as he tried to urge Rengoku's tongue to react to his touches, he had had a lover.
He wasn't surprised by that thought but felt intrigued by it.
With his Rengoku , he had spent the cold nights hunting against demons; he had trained with him, and they had shared everything.
His Rengoku was a sunny and cheerful man, always capable of giving him a smile and a phrase of encouragement.
Michikatsu was happy when Rengoku was with him.
Kokushibo pushed his body further against the Demon Slayer's, seeking the familiar warmth he had rediscovered in his mind.
However, no matter how much the Upper Moon tried to remember, he couldn't visualize his lover's fate.
Had the Demon Slayer Mark taken him away like so many others? Had he been killed by a demon?
Kokushibo pulled away, shocked by that thought, and his eyes ran up to those of the young man he was holding down.
A name remained suffocated in his mind, and for the first time, the image that formed before him appeared sharp and clear.
Lips wet and red, saliva sliding down the chin. His scarlet cheeks and rapid, frightened breathing. And finally, the eyes … tears had accumulated in the corners and threatened to fall at any moment. The young man gave him a look full of anger but also of fear and shame for the imposition to which Kokushibo had forced him.
«Why?»
That simple question, whispered in his ears by the ghosts of his past, led Kokushibo to remember again.
The hand that had deprived his Rengoku of life hadn’t been that of any demon but had been his.
With Muzan, Kokushibo had exterminated those who knew Sun Breathing, and Rengoku was one of them. He had taken his life, and the suffering and betrayed look Rengoku had given him had tormented him to the point of forgetting. Just as Kokushibo had also forgotten the faces of the other people he had loved.
As if burned, the Upper Moon removed his hand from the young Demon Slayer's face, and as if he could no longer bear his presence and proximity, he also moved away from his body.
The cold embraced him again, and with all the speed he possessed, the demon moved away from that place and from Rengoku.
Kokushibo didn't look back or desire to do so because it would have meant turning his gaze to that past that he wanted and had to forget.
As he tried to lock his thoughts and memories inside his chest again, he promised himself only one thing: he would never make the same mistake again.