Ever since Hiru appeared, the Hashira of the Demon Slayer Corps had been run ragged. No matter how busy things became, however, two Hashira were always kept by Ubuyashiki's side. He had objected many times, but it made no difference. Hiru even used it to mock him openly, saying Ubuyashiki had no authority at all, even while standing under the murderous glares of Obanai and the others.
On the day Hiru first appeared, Ubuyashiki had already realized that this was a demon of uncertain allegiance, one who acted without restraint.
After speaking with him alone, he became even more unwilling to let the others waste their strength protecting him. A demon who did not fear sunlight and whose Blood Demon Art was connected to the mind was not an opponent the current Demon Slayer Corps could handle. He could not gamble the Corps' safety on the other party's temporary goodwill.
That was why everyone at Headquarters, apart from his wife Amane, who insisted on staying by his side, had already been secretly relocated. The children had been sent away and protected, and a new Demon Slayer Corps Headquarters had been established elsewhere. What he wanted now was for the Hashira who insisted on guarding him to leave as well. Only then, if Hiru changed his mind, could the Corps' losses be kept to a minimum.
Thinking of this, Ubuyashiki felt a headache coming on. He showed none of it, however, and his expression remained calm and smiling.
"It's another fine day today. If I remember correctly, Mitsuri and Shinobu should be on duty this time. Tengen, Kyojuro, is there something you wished to discuss with me now that you've come to relieve them?"
"Yes! It concerns Hiru-san. I believe I must report this to you!" Kyojuro knelt respectfully on one knee, his voice ringing clearly. "I'm sure Shinazugawa and Iguro have already mentioned it to you. Not long ago, Hiru-san personally captured the second-ranked demon of the Twelve Kizuki and declared it a gift for Shinobu!
"Two days ago, Hiru-san also came to find me and insisted on accompanying me on a mission no matter what. During that mission, we encountered Lower Moon One of the Twelve Kizuki. That demon had fused its own flesh and blood with a train and intended to devour everyone onboard!
"I had planned to join forces with the lower-ranked Corps members and take action, but Hiru-san stopped me. In less than ten seconds, he turned the entire train, which had been transformed into the demon's flesh, into hard crystal! It was truly astonishing!"
Tengen could not help cutting in. "What about the people on the train? Can that Blood Demon Art transform humans? How does he treat them?"
"I'm not sure either!" Kyojuro turned slightly toward him. "The passengers had some bumps and bruises, but nothing life-threatening! Later, however, when someone woke up and began accusing us, Hiru-san cursed while knocking him unconscious. He did hold back his strength, but he did not hesitate at all!
"After that, an Upper Moon demon appeared. Hiru-san controlled the crystallized train and attacked that demon in an extremely incredible way. Then he told me the demon could no longer use its Blood Demon Art and told me to fight it!
"To be honest, I was no match for that demon at all. Fortunately, Hiru-san was there. We managed to stall until dawn, and when the sun rose, that demon died because it could not overcome sunlight. Though before it died, it did curse quite terribly!"
"Is that so... Another Upper Moon has fallen." The smile on Ubuyashiki's lips deepened slightly. "That truly is good news."
"I have even better news. Want to hear it?"
Kyojuro and Tengen, who had just been about to speak, both reached for their sword hilts almost at the same time. Their gazes snapped sharply toward the doorway, and when they saw Hiru, both of them frowned.
Only Ubuyashiki remained still.
"I wonder what kind of good news it is?"
"Well, let's just say it's news I consider pretty good." Hiru raised the box he was carrying, his smile looking distinctly ill-intentioned. "I caught another Upper Moon."
Tengen's brows drew together, his expression darkening. "You actually brought an Upper Moon demon into Headquarters?"
Hiru froze, then looked at Ubuyashiki in confusion. "Haven't you already moved everyone out? When I came in, I couldn't even find anyone to show me the way... Don't tell me you're worried about the house."
"Even so, you can't just bring a demon into..."
Hiru waved a hand, clearly uninterested in hearing Tengen finish. "How were the medicine and intel I gave you?"
Tengen paused. "Ah. The Upper Moon Six sibling demons already died at my and Iguro's hands. But that antidote you made was seriously awful."
"Awful? Good. It was supposed to be." Hiru gave a derisive laugh. "It took me quite a bit of effort to make an antidote that wouldn't interfere with the medicine's effects while still making sure it tasted awful."
A vein bulged at Tengen's temple, and he was about to say something when Hiru raised a hand and cut him off again.
"Can you beat me?"
"..."
"If you can't, then shut up."
Tengen: ...Shit.
"What exactly are you trying to do, Hiru-san?" Kyojuro's hand remained on his sword hilt. "No matter what, bringing an Upper Moon demon close to Oyakata-sama is far too dangerous!"
"I was just about to talk about that." Hiru casually tossed the box onto the floor nearby and looked at Ubuyashiki. "Move out. I'm going to use this house."
Ubuyashiki still wore a gentle smile. "What does Hiru plan to use it for?"
"The demon I caught seems to be Four? Five? Forget it, doesn't matter. Anyway, it's perfect for the Hashira to practice against. Right now, my Blood Demon Art is blocking him, so Muzan can't find this place yet. Once I remove the block, Muzan will be able to track him here."
"So Hiru intends to set a trap? Train the Hashira while drawing Muzan in."
"Talking to smart people really is easy." Hiru sat down on the box, his attitude casual. "Muzan has a demon under him who can manipulate space. I could find them if I spent the time, but I don't feel like going through all that trouble. I was originally going to have you buy a mountain, but since you happened to have cleared everyone out already, why don't you move and let me have this place?"
"Does Hiru have confidence in dealing with Muzan?"
"To be honest, absolutely none." Hiru shrugged. "But with your help, destroying the Infinity Castle and dragging him out until dawn shouldn't be too hard. How does that saying go again? Sunlight doesn't protect evil demons."