Rinko's life had been pretty full lately. "Full" was a generous way to put it, though. There wasn't much he could actually do. It was simply that Muzan hadn't found the next place to stash him yet, so wherever Muzan went, Rinko went too. From the outside, it looked like he was constantly being shuttled around, always busy, always in motion.
In reality, Rinko's job was to occupy the highest rooftop, serving as a lookout bird. Officially, it was "getting some air." Practically, it was watching the show.
Recently, Muzan had been taking Kokushibo along to wipe out Demon Slayers. Their combat power had reached the point where Rinko's mere presence on the battlefield would be a hindrance, so his current routine looked like this.
Shift locations, get tossed onto a roof, start "basking" in moonlight, watching stars, counting leaves, then get claimed back off the roof by one of them. Like they were entertaining a child, they would ask if he wanted anything to eat.
Muzan was usually the one who did the teasing.
Kokushibo was usually the one who did the "handling."
When Rinko was carried around like a small bundle, forced to drift through the entire battlefield, he would wonder what, exactly, Kokushibo thought he was.
"Is there… anything… you want to eat?"
Once that question came out, it felt even more like it.
Raised up high and forced to meet Kokushibo's gaze, Rinko eventually shook his head. He caught it clearly, that flash in the eyes of two adult men.
Disdain.
Directed at his "picky eating."
But Rinko didn't think it was his fault. First, his stomach didn't feel hungry. Second, his nose wasn't interested in those smells. And even if he compromised, his body still had its own opinion, an opinion that stubbornly refused to agree with theirs.
That was different from ordinary pickiness, the kind born from preference.
But to those two, it was all excuses.
And even so, if they truly sat him down and gave him something, Rinko would still, without hesitation, put whatever was shoved into his hands into his mouth, chew it up, and swallow it.
"I suppose I've spoiled you."
Muzan reached out and took Rinko from Kokushibo's hand.
"Rinko. You've been… completely… indulged."
This pause was even longer than usual. Kokushibo searched through his vocabulary until he found the most fitting word.
Rinko, who had done nothing and yet somehow felt he was being scolded, lifted his head.
No one answered him.
But silence could be its own kind of statement.
And right now, their meaning was obvious.
If someone truly had to bear responsibility for Rinko being "spoiled," it was because of Muzan's indulgence and support.
Rinko raised his gaze toward Muzan, the very one who had always backed his behavior and encouraged his little experiments. But the instigator said nothing, neatly removing himself from blame, greeting Rinko's stare with a smile.
Even though all of this had been granted by Muzan in the first place.
After Yoriichi Tsugikuni died, the mountain crushing Muzan's chest was finally lifted.
That suffocating sensation, like someone's fingers clamped around his throat, holding him at the edge of death, vanished the moment he confirmed that man's death. For a time, Muzan's mood stayed bright. He took Kokushibo and slaughtered the families of Demon Slayers again and again, in and out, seven times over. He also wiped clean every person connected to Sun Breathing.
After that, his mood looked even better.
And it was from that point on that Muzan began to spare attention for Rinko.
If you put it kindly, Rinko's temperament was gentle. But you could just as easily call it timid, withdrawn.
It wasn't a problem, not exactly.
But Muzan seemed inclined to raise him into something more outgoing, or at least to teach him to speak more, instead of turning into a mute whenever strangers were present.
Rinko's way of being had a trail of causes. His frailty. The misfortune he had endured as a human. All of it made him prefer not to provoke anyone and, even more, to avoid being noticed. It also left him with a kind of quiet pessimism, a refusal to expect much from anything. If you expected nothing, you wouldn't be disappointed. If you lived prepared to die at any moment, you wouldn't fear death when it arrived.
Changing that wasn't impossible. The difference lay in method.
The more direct, brutal approach was simple. Feed him more meat, make him stronger, train him until he was no longer fragile.
The gentler, subtler approach was to leave the situation as it was, and gradually shape his temperament without forcing the body to change.
The latter clearly took more time. It was also more troublesome.
Rinko wasn't good at fighting. Everyone who knew him agreed on that.
But Kokushibo gave Muzan another framing. He said Rinko's talent wasn't in battle. Rather than throwing him into a frontal clash where he traded blows with the enemy's strongest, it would be better to make him responsible for infiltration, probing, gathering clues. Or to assign him to support and distraction during combat.
But the most suitable role, Kokushibo said, would be retreat after battle.
And if Rinko's ability could be applied to other demons, his existence would become something far beyond expectation.
Muzan had experienced it firsthand.
If Rinko chose to hide himself, he became difficult to find.
"Rinko is like a flame," Kokushibo had said. "Precisely because it's not strong enough… people overlook it."
That was Kokushibo's view.
Muzan didn't want to lose a rare case like this, and he also didn't intend to strip Rinko of what made him special.
So he chose the second method.
Muzan had always been sensitive to shifts in other people's emotions, and even more so when it came to a child who was completely transparent before him. Everything Rinko saw, everything he thought, Muzan could witness.
A small hint here. An offhand reminder there. A little permission. A little privilege.
Just as Kokushibo said, Rinko was a child, and his head didn't work all that well.
So changing him wasn't hard.
It only required time.
And as demons, time was the one thing they never lacked.
Rinko could tell Muzan was indulging him. But that wasn't a bad thing. It was worth being happy about, those little requests that were casually granted. Muzan being willing to indulge him more was worth being happy about too.
So even knowing the road had been laid out for him, Rinko stepped onto it without hesitation.
By the time he realized something had changed, certain habits had already become natural.
After that long stretch of deliberate shaping, Rinko's temperament began to shift.
For instance, he was much livelier than before.
Sometimes he even dared to argue with Muzan for a few lines. And the moment he sensed he was losing, or noticed Muzan didn't look pleased, he would immediately slip behind Kokushibo, seeking shelter.
And when he sensed Kokushibo's displeasure first, he would hide behind Muzan instead.
Then, in a very small voice, he would mutter, "I think I made him mad…"
His years continued to accumulate, but because his environment never truly changed, his personality didn't mature with them.
If anything, he grew more childlike.
More like a normal child.
Muzan ran a hand through Rinko's short hair, weighing the thought in silence.
But it wasn't a bad thing.
Keeping a child who was a little more lively was, honestly, more interesting than keeping that silent little mute.