Kuwajima had never imagined that the next time he saw Hiru, it would be to receive news of his disciple's death.
"I'm sorry. I began investigating as soon as I could, but I was still too late. I couldn't save him. He was killed by a demon."
Kuwajima accepted the magatama from Hiru's hand. The sharp, discerning eyes that once seemed able to see through anything were now clouded with tears.
"I see… I see. So that child fought properly until the very end…" His voice trembled. "I always knew that, because of what he went through as a child, he struggled to trust others. I worried he might run when it truly mattered. But I never thought… that in the end, he would fight so well…"
He began reminiscing about the day he first took Kaigaku in—how he caught the boy stealing money to gamble, how he forced him to quit, how he patiently taught him what it meant to be a decent man.
One story followed another, even the smallest details recalled with painful clarity.
It had been a bond he cherished deeply.
Yet some people never see the blessings already in their hands. They only fixate on what others possess, lamenting how unfair the heavens have been to them.
Hiru remained at the old man's side the entire time, listening quietly and without interruption.
In the end, it was Kuwajima who fell silent. Though sorrow still lingered on his face, he urged Hiru to return to his duties rather than waste time listening to words that could no longer change anything.
"How could they be useless words?" Hiru lowered his gaze to the small-framed elder and offered a gentle smile. "Those are precious memories. I should be thanking you for sharing them with me."
Kuwajima waved him off, unwilling to dwell on it further.
"Go. I no longer fight. I have plenty of time to sit with my grief. But you can't remain here with me. Every demon you slay or capture is one fewer person who has to suffer as I do. Go. Go."
"…Then I shall take my leave. Please take care of yourself."
Kuwajima watched Hiru walk away. He stood there for a long time before finally turning back with a sigh.
In that instant, his once-straight back seemed to bend.
"Kaigaku… this time, you should have run…"
...
Zenitsu felt like he simply couldn't figure the siblings out.
The older sister, Kamado Nezuko, looked sweet and adorable at first glance. In battle, though, she was decisive and frighteningly skilled with her Breathing, always going straight for a killing blow against demons. She was the kind of swordsman who made everyone around her feel safe.
And yet, she seemed strangely prone to dizziness at the sight of blood. Even after a brutal fight, her face would stay pale.
The younger brother, Kamado Takeo, was—objectively speaking—only slightly less handsome than Zenitsu himself. Gentle by nature and quick on his feet, he delivered sharp, precise strikes even while carrying a box on his back.
But his stamina was clearly lacking. His breathing often grew ragged, and he would suddenly collapse in a cold sweat, only to apologize and force himself back up moments later.
What unsettled Zenitsu most, however, was that box.
From inside it, he could hear the unmistakable presence of a demon.
And yet, woven into it was a voice so gentle it made his chest ache.
Why would a demon sound like that?
Zenitsu was completely lost.
After fighting alongside the siblings, his confusion only deepened. On the way back, once their wounds had been bandaged, he finally pulled Takeo aside and voiced the question that had been gnawing at him.
"Huh? Why am I carrying a demon?" Takeo looked troubled. "Um… how do I explain this… He's my brother."
"Huh?! Your brother?!"
"Yeah." Takeo nodded with a small smile. "By the way, thanks for helping us protect the box, Zenitsu. It was daytime, so if sunlight had hit it, that would've been bad. But now that it's night, it's fine. Why don't you meet him?"
"Is that really okay?" Zenitsu rubbed his arms uneasily. "That's a demon… Demons eat people."
"My brother isn't an evil demon. He doesn't eat people." Takeo stopped in front of a door and reached for it. "Though that Inosuke we ran into today… I've got a feeling he's going to be trouble. Huh? What's going on here?!"
Inside the room, a handsome yet muscular boy was pinned face-down on the floor by another youth about the same age, his arms twisted behind his back.
"Have a proper duel with me using your real strength! This doesn't count! It doesn't count!"
"I told you, you're injured. Stop struggling," the deep red-haired boy sighed. "And I don't want to fight someone from the Demon Slayer Corps."
He glanced up at the stunned pair in the doorway.
"Takeo, how are your injuries? Where's Nezuko?"
"I'm fine. It's nothing serious. Sis is finishing up the bandages and will be back soon…" Takeo glanced at Zenitsu, who was clinging tightly to his sleeve, then looked back at the two in the room. "What happened?"
"I was just helping you lay out the bedding when he suddenly charged at me, shouting about a decisive match," the red-haired boy explained. "I was worried he'd reopen his wounds, and I didn't want to fight him, so I had to hold him down."
"What a headache…" Takeo sighed and looked down. "Inosuke, even if you want to challenge my brother, you should wait until you've healed—"
"I am the invincible King of the Mountains!" the beautiful boy named Inosuke roared as he struggled. "A scratch like this won't affect my fighting strength! Let me go! We're settling this now!"
"Even the King of the Mountains has to take care of his body," the red-haired boy replied helplessly. "And you can't beat me anyway. You're too slow compared to our teacher. If he found out I couldn't dodge something that slow, he'd be disappointed. Besides, I'm part of the Demon Slayer Corps too. Members aren't allowed to fight each other. So I won't fight you."
"You bastard! Are you looking down on me?! Duel me! Let me go! Duel!"
"No! You need to rest! And I'm not looking down on you! I'm just following the rules!"
Zenitsu clung to Takeo's sleeve, staring blankly ahead.
He was starting to question his life choices.
Was it that the Demon Slayer Corps had an unusually high concentration of demons…
Or that he just happened to keep ending up surrounded by them?
Why was it that no matter where he went, he kept running into demons?
Watching the farce unfold, Zenitsu sank into deep self-doubt.