This time, Muzan hadn't come merely to take a look. He was here to take Rinko with him.
Not because Rinko had learned enough to "graduate" from Kokushibo, though.
It was simply that Tamayo had made some progress. Passing by on the way to her, Muzan stopped in, saw that Rinko looked to be in good condition, and decided to bring him along as well. It would be convenient to have Tamayo check him over, and to record whether this period of training under Kokushibo had done anything to promote Rinko's growth.
Calling it "taking him away" wasn't quite right.
It was more like Rinko had been granted a short break, temporarily picked up by his guardian to accompany him while he handled business.
So before leaving, Rinko was still waving at Kokushibo, politely promising to meet again next time. Only when he was lifted up did he shut his mouth.
Kokushibo also liked to carry Rinko by lifting him. The oversized robe on Rinko's body was like cloth used to wrap luggage, and Rinko was the "luggage" bundled inside.
Muzan held him differently.
Rinko had seen this kind of hold among humans, usually when they carried kittens or puppies. One arm slid across the front, hooked in, drew close, and lifted, pressing the animal to the chest and pinning its body with the forelegs. With cats and dogs, their front paws would stretch straight and gradually slip downward.
But Rinko wasn't a cat or a dog.
He could fix himself in place against the arm holding him.
Objectively speaking, Kokushibo's method seemed more convenient. But Rinko still preferred Muzan's. After all, the view from being held against someone's chest and the view from being dangled at arm's length were completely different.
And when he was carried like luggage, he always felt like he might bump into something.
"Are we going to see Tamayo?"
"So you still remember her."
When Muzan glanced at him, Rinko nodded.
There were not many names he needed to remember, after all.
Muzan. Kokushibo. Tamayo. And his own name, Rinko.
As for the demons he met by the roadside, before he could even ask their names, Tamayo would chase them away. And the ones he met later, before they could open their mouths, Kokushibo's presence alone scared them off.
"She moved to a new place. I heard there's news of the Blue Spider Lily there, so we're going to take a look."
The Blue Spider Lily.
A term Rinko had heard again and again.
Demons could not move under the sun. Sunlight would burn their skin and flesh. But Rinko, in truth, did not like the sun all that much, so he did not mind.
Muzan did mind.
He wanted to become what he called the ultimate life-form. Rinko didn't really understand the phrase. Muzan explained it in simpler terms, and in the end it came down to this: he wanted to overcome his one weakness, his fear of sunlight.
Tamayo looked a little surprised when she saw Rinko.
Her expression didn't shift much, but Rinko could still sense the subtle change in the air. Only that much.
As promised, Rinko brought Tamayo a small gift.
Unripe acorns threaded on a single string into a small bracelet.
Rough and clumsy.
But Tamayo didn't seem to dislike it.
The two adults went out to search for what they needed, and Rinko was left behind in the house to wait for their return.
That was reasonable.
He wasn't good at fighting. He wasn't good at dealing with Demon Slayers. If he was discovered, he would be the hardest one to escape. Muzan was thinking for his sake.
Not becoming a burden was also a form of recognizing yourself clearly.
That was what Kokushibo had told him.
For someone like him, sometimes you had to find your place.
So Rinko accepted the arrangement gladly.
Much later, he would think that it was the single most correct decision he had ever made.
And Muzan would agree.
Perhaps that was also why Kokushibo and Muzan had always gotten along fairly well.
Rinko sat quietly inside the house, reading.
What alerted him was instinct.
An indescribable instinct, as though something had gripped his heart, making breathing and heartbeat difficult.
Then, after he didn't know how long, that crushing pressure vanished in an instant.
He heard someone calling him.
Tamayo always told him not to go out on his own.
But Rinko recognized that voice.
Even without understanding why, Rinko obediently followed the pull in his blood, searching along the thread it drew through his veins. The journey was long, but he still moved as fast as he could.
He found him.
Or rather, Rinko wasn't sure that the mangled, stitched-together mass of flesh could still be called Muzan.
(Come here. Rinko. Come here.)
The voice spun inside his ears, inside his skull, repeating the same command over and over, like something nameless trying to lure him.
Rinko walked over, knelt quietly, and pulled the writhing lump into his arms as it struggled to knit itself back together, trying to regrow and recover.
"I'm here, Lord Muzan."
That seemed to be some kind of signal.
The flesh, which had been still, suddenly surged and swallowed the hand that held it, then the arm, then the legs folded beneath him as he knelt.
It was the first time Rinko had ever experienced anything like this.
The severity of the injuries, and the one who had caused them, were both beyond anything he knew.
Muzan's body tried to regenerate rapidly, but it couldn't keep up with the rate of devouring.
The experience wasn't something you could call pleasant.
Pain, for Rinko, was usually dull and numb. He didn't feel it clearly. But his body would regrow, and then instantly lose connection again as it was eaten away. That stunned, disconnected feeling, the inability to link with his own flesh, left him confused.
He didn't know what had happened. He didn't know what he should do.
Only instinct screamed at him that this place was not safe.
At the very least, he needed to find somewhere safe first.
It turned out that awareness granted later in life was useless before instinct.
Fear of death and the desire to live drowned everything in a single wave.
In that moment, Muzan didn't even know what he was doing.
His only thought was to run.
To live.
To hide.
To hide somewhere no one would ever find.
Everything else was thrown away. Blue Spider Lily. Sunlight. All of it.
When death truly brushed close, only the urge to survive remained real.
So when he opened his eyes and saw Rinko reduced to only part of a body and a head, he was surprised.
But after a brief thought, it also seemed reasonable.
The surprise was that Rinko had appeared at his side. The surprise was that he had ended up inside a house that seemed relatively safe.
And the reason was obvious. Rinko was here.
Which meant Muzan must have called him without thinking. The little thing rushed over, then naturally brought him somewhere safer.
As for Rinko's shattered body, that was because Muzan had devoured him unconsciously to restore his own flesh. The wounds left by that blade were more severe than anything he had ever suffered. No matter what he did, it was as if the injury still burned inside him.
He needed external nourishment to recover.
(I raised you for so long. You should be useful to me, Rinko.)
As Muzan's mind cleared, he remembered the act of devouring.
He had eaten flesh by instinct in order to regenerate. And the boy had resisted with his own remarkable healing ability, until his recovery could no longer keep pace with what was being taken.
The rising sun had saved Rinko's life.
Muzan didn't know if Rinko could still hear him.
The boy was asleep, asleep so deeply it was absurd. Once the devouring stopped, his body regenerated quickly, but his consciousness remained buried. To lose half his body and still sleep, it was unimaginable.
Muzan had not called Rinko because he trusted him.
It was simply that once he realized Rinko's unusual capacity to withstand blood, he had been gradually increasing the amount of his blood within the child.
Setting aside any other thoughts and speaking only with cold reason, Rinko was like a moving blood bag, a small insurance policy.
If Muzan was ever injured, eating this child would at least ensure he didn't lose the ability to resist.
The final fate of stray cats and dogs was to be buried somewhere in wasteland no one remembered. Compared to that, being eaten and becoming part of Muzan's strength was, for Rinko, a better ending.
When darkness fell, the sleeping boy finally woke.
Muzan watched Rinko slowly open his eyes. The child looked dazed, staring at the ceiling for a long moment before turning his gaze toward him.
What would his first words be?
Fear?
Terror?
Pride in sacrificing himself?
"You ran into something. It looks like you were badly hurt. Are you alright now?"
Rinko looked at him with calm, unmoving eyes.
In a tone that did not belong to the present moment, he expressed concern and confusion.
Even after being dragged back from the edge of death, even after having his body devoured, Rinko showed no resistance, no dissatisfaction.
Of course.
Rinko had always listened.
If Muzan said he wanted to eat him, Rinko would probably offer his neck to his mouth.
Muzan suddenly lost interest in feeding.
He withdrew his hand. Rinko recovered quickly. He slowly sat up and flexed his fingers.
"I'm glad you're still alive."
Muzan lifted his eyes.
At first he thought Rinko was speaking about his narrow escape.
But then he met that gaze again, filled with quiet delight, the voice and smile matching each other perfectly.
"I'm glad you're still alive."
Rinko was happy for him.
Happy that Muzan was still alive.
Lord Muzan was a very good person.
Some animals remember the first thing they see when they open their eyes. Whether it's a person or an object or their parents, they imprint on it and treat it as their parent.
For Rinko, memory was limited.
His box held many things. Turn it over and shake it, and the pieces scattered everywhere. The clearest piece was always Muzan. His face, his voice, his clothes, his habits. So many fragments that assembled into a complete presence.
So even though they were apart for long stretches later, even though they lacked time together, the earliest memories were left by Muzan. And in the years that followed, it was Muzan who linked those scattered fragments into a single line.
It became something like a parent.
Muzan was not his father, nor his mother.
But in Rinko's poor dictionary, there was no better word, so he borrowed that one as a substitute.
Tamayo was also a very good person.
Rinko didn't like most people in the world.
Adult men, adult women, he didn't like them. Their height, their build, the way hands lifted, the way voices rose, every detail made him step back without thinking, as if only behind Muzan's back could he be safe.
But that wasn't right.
It would trouble Muzan.
So Rinko forced himself to face the first unfamiliar adult woman.
She was the first demon Muzan had ever brought him to meet. After that, much of his time was occupied by her name.
Rinko did not know Tamayo. He had never seen her before, and had rarely heard of her. Yet at first glance, he felt he did not dislike her.
She was gentle.
Very, very gentle.
Rinko was willing to share every small discovery that made him happy with her. At first, Tamayo mostly didn't understand, but after she asked and received an explanation, she would look… happy too.
As for Lord Kokushibo, that was a different kind of existence entirely.
Rinko had seen demons before.
During the years he stayed with Tamayo, they sometimes went out at night, and they would encounter other demons. Humans retained certain traits after becoming demons, and certain traits were strengthened. Individual differences meant demons could look like anything.
Horns were common.
Fangs and claws were even more common.
Demons like Muzan and Tamayo, who could maintain a human appearance, were rare.
And demons like Rinko, who had almost no change besides sharper teeth and slit pupils, were also rare.
But Rinko had never seen a demon like Kokushibo.
Tall.
Far too tall.
He stood there like a wall. Simply standing was enough to press down on the air, making Rinko forget the rhythm of breathing.
Neat clothes. A sword longer than Rinko himself. A broad hand resting on the scabbard.
Then Rinko looked up, and that face came into view.
A gaze looking down from above, like an asura from a hell realm stepping into the human world.
Six eyes filled most of the face.
Gold set inside deep crimson.
Even the tied-back long hair was dark red.
Flame-like markings crawled across his skin.
It far exceeded Rinko's understanding of the word intimidation.
"Demon" was a concrete word, a kind of creature.
But Rinko had also learned from books that before people truly faced demons, humans described them in a more unreal way. To them, demons were not an entity with a body, but something vague and unseen. The words used were mostly terrifying, dreadful, eerie.
Before, Rinko didn't understand.
Now he suddenly understood the other meaning of demon.
In the middle of the night, he had truly met a demon.
It was a first meeting so shocking that Rinko believed he would never forget.
He overestimated his own mind, and underestimated time.
Decades were enough to blur Muzan in his memory. A few months were enough for him to see clearly that the being before him was not a fiend crawling out of hell, and would not casually crush his skull.
Even if, later, in training, Kokushibo came close to doing exactly that countless times.
Rinko's small head could only hold so much.
So what remained, after all that time together, was not the terror of Kokushibo's face, but the cold, long-silent heart beneath it.
Kokushibo and Tamayo were completely different existences.
But both left a heavy, vivid stroke inside Rinko's mind.
So when he sat there being devoured, when his body was reduced to less than half, what he felt was not fear.
Only regret.
Because this had been a life worth being glad about.
A life as beautiful as his dreams.
If he could have lived on, he would have been happy.