The evening wind carried a faint chill as it swept through the narrow streets of the western district.
When Tomioka Giyu arrived at the door of Tamayo Hall, the light inside was already on. The warm glow filtered through the paper windows, revealing two dim silhouettes within.
He knocked softly. The door soon opened, and Yushiro appeared, still wary but no longer hostile as he had been the day before.
"Tomioka-san."
Tamayo's voice came from within the room. "Come in."
Giyu stepped inside. Tamayo sat at the table, the letter from Oyakata-sama laid neatly before her. It was clear she had been contemplating her decision for some time.
Yushiro stood beside her, gripping the hem of his robe, his expression uneasy yet silent—he had clearly already been told of her choice.
"I've made my decision," Tamayo said, lifting her gaze toward Giyu, her eyes calm but resolute. "I'll cooperate with the Demon Slayer Corps to destroy Muzan. But I have two conditions."
Giyu nodded. "Please, tell me."
"First," Tamayo said seriously, "the Corps must fully support my research—without question or hesitation. I'll need medical herbs, equipment, and the right facilities. My experiments may be dangerous, but if you want results, I'll need your full cooperation."
"Second, the Corps must guarantee my safety—and Yushiro's. You cannot treat us as enemies simply because we are demons. As long as we neither harm humans nor betray the Corps, you are forbidden from pointing your Nichirin Swords at us."
Her voice was steady but firm.
Both conditions were entirely reasonable. Giyu didn't hesitate. "I agree. Oyakata-sama has already said you'll be treated as comrades. These terms are acceptable to the Corps."
At his words, Yushiro's tense shoulders relaxed slightly. He glanced at Tamayo, his eyes softening with relief. If she trusted them, that was enough for him.
"Then we leave tonight," Giyu said, standing. "We'll head to headquarters now—Oyakata-sama is waiting for news."
Tamayo and Yushiro exchanged a brief look before both nodded.
Yushiro swiftly packed their essentials—mostly Tamayo's medical books and herbs—while Tamayo carefully tucked the handwritten letter from Oyakata-sama into her sleeve.
The three stepped out into the night.
The road was silent, broken only by the sound of footsteps and the soft fluttering of the crow's wings. Giyu led the way, the lantern's faint light guiding them through the darkness. Behind him, Tamayo and Yushiro walked side by side, speaking quietly to one another—their tones filled with both cautious hope and unspoken tension.
By the time they reached the Demon Slayer Corps Headquarters, it was already past midnight.
The compound lights still glowed warmly; someone was clearly waiting for them.
At the main hall, Giyu stopped and bowed respectfully toward the interior. "Oyakata-sama, this is Tomioka Giyu. Tamayo-san has agreed to cooperate with the Corps."
From within came Ubuyashiki Kagaya's gentle voice. "Please, come in."
Giyu slid the door open and led Tamayo and Yushiro inside.
Kagaya sat in his wheelchair, his complexion pale as ever, but his expression calm and composed. A few attendants stood nearby, quietly reporting matters of the Corps.
When he saw Tamayo and Yushiro, there was not a hint of fear or surprise in his face—only a warm, welcoming smile.
"Giyu," he said first, turning his gaze toward the Water Hashira, "you've done well. Convincing Tamayo-san to join us is no small feat."
Giyu bowed slightly and stepped back to stand beside Oyakata-sama, leaving the conversation to him.
Ubuyashiki Kagaya turned his calm gaze toward Tamayo, his eyes free of judgment—only respect. "Tamayo-san, welcome. Thank you for choosing to trust the Demon Slayer Corps and for agreeing to stand with us against Muzan."
Tamayo looked at the frail man before her, her heart tightening slightly.
She could sense it clearly—the deep, corrosive curse that lingered within his body. Unlike Muzan's endless, malignant vitality, the life within Kagaya was burning out rapidly, flickering like a candle in the wind that could be extinguished at any moment.
After a brief silence, she spoke softly, "Your body… the curse is severe. You may not have much time left."
The room fell silent. The attendants' eyes flickered with sorrow, but none of them refuted her words.
They all knew. They simply refused to speak it aloud.
Kagaya, however, smiled faintly, his tone as calm as if he were discussing someone else's fate. "I've long been aware. The Ubuyashiki family has carried Muzan's curse for generations. None of us live long.
From the day I was born, I never expected to grow old. My only wish is that, in my lifetime, Muzan will finally be destroyed—that this war, which has lasted for centuries, will end with me. I want the curse of the Ubuyashiki family to die here."
His voice was quiet but carried an undeniable weight. "For that goal, I will do anything. I will use any means necessary—no matter the cost.
Even if it takes my life, even if it means welcoming a demon as an ally… if it leads to Muzan's downfall, it's worth it."
Tamayo looked into his unwavering eyes, and the last trace of hesitation within her vanished.
The man before her was fragile in body, yet his will was unbreakable. His conviction burned brighter than any life force she had ever seen.
Following such a person… perhaps this time, she truly could reach her goal.
She drew in a deep breath and said solemnly, "Oyakata-sama, while I cannot completely lift your curse, I can prepare a medicine that will suppress its effects. It will ease your pain and perhaps allow you to live long enough to see Muzan's end with your own eyes."
Kagaya's eyes brightened, a rare spark of joy in his expression. "Truly? Then I must trouble you, Tamayo-san."
"It's no trouble."
Tamayo shook her head gently. "It's something I should do. After all, we're comrades now."
At that word—comrades—Yushiro's lips curved faintly, almost imperceptibly.
He looked at Tamayo's focused expression, then at Kagaya's kind smile, and for the first time, he felt that perhaps this choice was the right one.
Standing beside Kagaya, Giyu exhaled quietly, relief washing through him.
Tamayo's alliance was a crucial step forward. Her knowledge, her research, her insight into Muzan—all of it would become invaluable weapons in their fight.
The warm glow of the lamps lit each face in the room.
The path ahead would still be hard, and Muzan's shadow still loomed over them, but at that moment, something new began to stir—something bright and fragile called hope.
Kagaya instructed his attendants to arrange rooms for Tamayo and Yushiro, and reminded Giyu to escort Tamayo the next morning to inspect the laboratory prepared for her use.
Everything was proceeding smoothly. With Tamayo's arrival, the plan to defeat Muzan had taken a solid, decisive step forward.
When night grew deep, Giyu stepped out of the main hall and looked up at the moon hanging over the quiet compound. Determination filled his chest.
He knew there was still much to do.
Now, he had more allies than ever—and a clearer purpose than he'd ever known.
This war that had lasted for hundreds of years would end with their generation.