Akira reached into his coat and withdrew a small, exquisite glass vial. The craftsmanship alone made it obvious that this was no ordinary container.
"I want to trade all the Yoriichi Type Null units for this," he said calmly.
A ripple of surprise passed through the gathered crowd.
All eyes were fixed on the vial in Akira's hand. At first glance, it looked like a potion, yet the delicacy of the glass, the faint glow of the liquid inside, made it feel far more valuable than any medicine they had seen before.
Erika froze.
She recognized it instantly.
That wasn't just some rare or expensive potion.
It was the rare and expensive potion.
Phoenix Tears.
Even though Erika was part vampire, she had never been especially interested in the deeper side of the supernatural world back in their own world. Still, she had grown up surrounded by it. She had learned enough from her mother, from Akira, and especially from her brother, to know exactly what this vial meant.
She had seen it once before. Not in person, but in an illustration, etched into the pages of one of her brother Iori's books.
Back then, he had explained it to her in simple terms.
A legendary healing elixir.
So rare that entire magical factions might possess one vial, if they were lucky.
Now that same mythical substance sat casually in Akira's hand.
Her thoughts raced.
"What is he doing?"
And worse, this wasn't just about rarity.
There were mission restrictions.
Magical items from their original world were regulated by the equilibrium function of the Star Soul System. Using them here, especially something like Phoenix Tears, could directly affect their mission evaluation.
Penalty, Reward rank reduction, and Unknown consequences.
Erika stared at the vial, then at Akira's back. She had no idea what he was planning.
Meanwhile, a silent argument was unfolding, one no one else could hear.
"Brother… did you really think this through?" Selena's voice echoed sharply in Akira's mind.
"I did," Akira replied without hesitation. "I know I could get the Type Null units from them easily. But I also wanted to save him. He helped me a lot… and a happy ending can't really be called happy if he dies now."
Selena didn't let it go.
"Yeah, but did you forget about the mission evaluation? Even giving that away will affect it, you know."
Akira exhaled slowly.
"I thought about that, too. Even if the reward rank gets reduced, it's fine. I'm strong on my own."
There was a pause, then Selena's tone changed, sharper than before.
"And did you think about Erika-chan?"
Akira froze.
"You won't just reduce your own evaluation. You'll reduce hers, too. Did you even discuss this with her?"
He completely forgot about that.
"…I didn't", he admitted quietly. "I forgot."
Ever since they were children, Akira had always been like this. making decisions on the spot, charging forward without hesitation. And Erika, more often than not, would follow him, complaining along the way but never truly stopping him.
Because of that, he had grown used to moving ahead without asking.
Selena sighed.
"Brother. Listen. Right now, she's your partner. Any choice you make affects her, too. You can't decide something this important on your own anymore."
Akira felt the weight of her words settle in.
She was right.
They weren't children anymore. And even back then, doing things without asking hadn't really been right either. The truth was, if Erika had ever truly objected, he would have stopped immediately.
But she usually went along with him.
So he stopped asking.
"I need to change", he realized. "If we're going to be partners from now on… I can't keep doing this."
After gathering himself, he replied. "Yeah,you're right. I should have talked to her first. I'll do that from now on."
He turned his attention inward again and reached out.
"Erika… can I do this?"
Erika was a bit startled by the sudden telephatic message.
"Huh…what…Why?" she asked telepathically.
"Because I want to save his life, it would be too sad if he dies," Akira answered honestly.
There was a brief pause.
Then Erika replied, "…Okay."
She didn't mind if the rewards were reduced.
As far as she is concerned, saving a life was more important than those rewards.
Relief washed through him.
With her permission given, Akira lifted his gaze once more and returned to the present.
"So," he said calmly, looking directly at Kagaya, "what do you say?"
Kagaya spoke at last, his voice calm and measured.
"May I ask… what exactly is it?"
Akira nodded and explained plainly, "It's called Phoenix Tears. An extremely rare healing potion. According to legend, it can instantly heal injuries and restore health, even for someone who is near death."
The moment those words left his mouth, shock rippled through the gathering.
Even the Hashira, who had faced demons without flinching, stiffened.
Then Kagaya asked again, gently, but firmly.
"That sounds like a treasure beyond measure. Is it truly right… for you to give something like this away?"
Akira answered without hesitation. "It's fine. I already got permission from my sister."
"Why are you making me sound like some kind of terrifying family head? And you can't do anything without my permission," Selena's voice cut in telepathically.
"I'm just setting the atmosphere, alright," Akira replied calmly. "If I frame it as an order from you, it sounds like a transaction between organizations instead of individuals. That way, it's easier for them to accept."
"You're really just dumping everything on me," Selena shot back.
Akira continued aloud, unfazed. "My sister wouldn't be able to accept the Type Null units for free. She's very strict about these things, family rules, and all. So it would actually be better if you accepted this trade."
Both Erika, who was sitting beside him, and Selena, who was watching from the castle, gave him the same strange look.
"How can he lie like this easily with a straight face?"
Before either of them could say anything, Shinobu suddenly spoke up.
"… Can that potion heal Oyakata-sama?"
The air froze.
It felt as though everyone had stopped breathing at once.
Akira met her gaze and nodded. "Yes, it can."
He continued evenly, "Phoenix Tears can't heal curses. But Muzan is dead now, and the curse on the Ubayashiki bloodline is gone. With the curse removed, this potion can fully restore his body."
At that, hope spread through the courtyard like a quiet flame.
Both the Ubuyashiki family and the Hashira turned their attention toward Kagaya, their gazes filled with something fragile yet desperate. Even though Kagaya could not see them, he could feel it, the weight of their expectations, their wishes, their unspoken prayers.
He could not bring himself to disappoint them.
Slowly, Kagaya lowered his head.
"…Then I will accept," he said softly. "Not just for myself alone, but for my family as well."
Akira stepped forward and placed the small glass vial into Kagaya's hand. With Amane's gentle support, Kagaya lifted it and drank.
The effect was immediate.
Before their eyes, his body began to change.
The dark discoloration along his skin faded, as though ink were being diluted drop by drop in clear water. The sickly pallor that had clung to him for so long receded, warmth returning to his face. The cruel, branching scars that had spread like rot across his flesh stopped their advance, then slowly lightened, as if his body itself were rejecting them.
And then.
"I… can see."
Kagaya's voice trembled.
His eyes, once clouded and lifeless, returned to clarity.
For a heartbeat, the world stood still.
Then voices broke.
Gasps. Sharp intakes of breath. Some fell to their knees. Others covered their mouths. A few simply began to cry.
Kagaya turned his gaze toward them, taking in the sight before him.
"So… this is how everyone looks now."
Tears welled in his eyes.
He then turned to Akira and bowed his head deeply.
"Thank you," he said. "Not as the head of the Demon Slayer Corps… but as a man who has been given back his sight. And his time. Now, I can spend more time with my family."
At that, not just Kagaya but everyone bowed toward Akira.
Startled, Akira waved his hands quickly. "N-No, really, don't worry about it. Just think of it as a transaction."
Even so, gratitude filled every expression looking back at him.
No one there would ever forget what he had given them.
After everyone finally calmed down, Kagaya spoke again.
"So… are both of you leaving soon?"
Akira nodded. "Yes. I was planning to give everyone a huge victory feast first. After that, we'll leave."
"I see," Kagaya replied softly.
Around him, the others exchanged quiet looks.
They wanted to help Akira and Erika on their journey, truly wanted to, but didn't know how. Both of them were already strong beyond measure, and there was little they could offer that would truly be of use. The realization left them feeling helpless, unable to properly repay what they had been given.
Just then.
Caw! Caw!
Two Kasugai crows burst through the room, startling everyone.
Raven and Rose swooped down at once, flapping wildly before landing near Akira and Erika.
"Don't leave us alone!" Raven cried.
"Yes, take us with you!" Rose followed immediately.
Akira and Erika exchanged glances.
Throughout this mission, the two they had spent the most time with, aside from each other, were these crows. They had fought together, traveled together, and shared countless moments. The thought of leaving them behind felt unexpectedly heavy.
At the same time, both Akira and Erika sent a telepathic message.
"Can we take them with us?" Erika asked.
"Yeah, I want to keep them", Akira added.
Selena's reply came instantly.
"Sure. You can even take a human with you if you want."
With permission secured, Akira turned to Kagaya.
"Would it be possible for us to take them with us?" he asked.
Erika looked at him as well, clearly hoping for the same answer.
Kagaya smiled.
"Of course," he said. "These two have always been a little distant from the other Kasugai crows. They're only truly close to each other… and it seems they've formed a strong bond with you as well. You may take them with you."
Relief washed over both of them.
"Thank you," Akira and Erika said together.
"Thank you!" Raven and Rose cawed happily.
After that, Akira discussed the feast he wanted to hold, how he planned to invite everyone he had met, even the swordsmiths from the Swordsmith Village. It would serve as a proper victory feast to celebrate the defeat of Muzan.
Kagaya agreed without hesitation.
A few days passed.
And then, the day of the feast arrived.
The feast began after nightfall.
Lanterns were hung throughout the Ubuyashiki estate, their warm light swaying gently in the night breeze. Long tables filled the courtyard, overflowing with food, steaming pots, grilled meats, fresh vegetables, and sweets piled high like small mountains.
Zenitsu stared wide-eyed at the scene.
"W-WAIT, YOU MADE ALL OF THIS!? BY YOURSELF?" he shouted.
Akira lifted a hand casually. "I had some help."
Behind him, several Type Null units moved with precise, almost comically careful motions. They stirred pots, plated dishes, and sliced vegetables with flawless symmetry.
"They're… cooking?" Inosuke squinted.
"THEY'RE EVEN BETTER AT THIS THAN ME!"
"Inosuke," Tanjiro said calmly, "you can't cook."
Kotetsu, the swordsmith boy, stared in awe. "How did you make them cook? That's amazing!"
"I programmed them for assistance tasks," Akira replied. "Turns out cooking is just applied optimization."
Rengoku laughed loudly, already holding a full bowl.
"EXCELLENT! FOOD MADE WITH SCIENCE AND SPIRIT! IT'S DELICIOUS!"
Everyone ate happily. Demon Slayers laughed, talked, and enjoyed themselves at last; they had finally won the war against demons.
Tanjiro laughed freely as he ate, and Kanao quietly ate beside him. Nezuko tasted everything with delight while Zenitsu pestered her endlessly. Genya argued with Inosuke over meat skewers. Aoi scolded people who grabbed seconds too quickly. The three little girls from the Butterfly Mansion darted between tables, giggling.
The Hashira relaxed, truly relaxed, for the first time in years.
Shinobu and Giyu argued over something trivial. Mitsuri ate an astonishing amount of food while Obanai sat quietly beside her. Sanemi and Gyōmei ate in silence. Rengoku ate loudly with his brother. Muichiro somehow managed to fly paper airplanes with other Demon Slayers while eating a skewer. Tengen enjoyed the feast with his wives, basking in the moment.
At the edge of the celebration, Tamayo and Yushiro sat quietly with their cat. They barely touched the food, simply enjoying the atmosphere. This victory belonged to them, too.
In the distance, the swordsmiths from the Swordsmith Village enjoyed themselves as well. They had all helped Akira create the Type Null units, so he had invited the entire village here.
Kotetsu and Kanamori ate happily with others, Haganezuka devoured mitarashi dango, and Chief Tecchin drank sake with elders, and the former Hashira, Urokodaki Sakonji, Kuwajima Jigorō, and Rengoku Shinjurō, all of them relieved that the war was finally over.
Farther still, Kagaya Ubuyashiki and his wife Amane ate peacefully with their children. They looked genuinely happy, savoring the simple joy of being together.
High above, perched along beams and rooftops, the Kasugai crows and Zenitsu's sparrow, Chuntaro, also received their share of food. They, too, were not left out.
On that night, everyone ate, laughed, and celebrated.
They had won.
And their long fight was finally over.
The next day… or rather, night.
Akira and Erika stood in the room assigned to them at the Butterfly Mansion, quietly packing their things.
"I'm going to miss this room," Akira said, looking at the room.
"Yeah… seems like it," Erika replied, a wistful expression on her face.
They had spent so much time here. They had grown closer here. Erika had even drunk Akira's blood every night here. Somewhere along the way, the room had stopped being just a place to stay and had become something closer to home.
That made leaving it unexpectedly difficult.
"We can always come back," Akira said. "Don't worry."
Erika shook her head slightly. "It's not about coming back. It just feels like… a chapter of our lives is over or something. Leaving this place means going to the next stage of our life, so I feel a bit wistful, I guess."
Akira nodded. "Maybe this really is the final chapter of this arc. Makes you wonder what the next arc will be."
"But we have to keep moving forward, right?" he added.
"Yes," Erika said softly. "We have to keep moving forward."
After that, they gathered all their belongings in the room and stored them into their inventory.
Akira made sure to store everything he needed as well: the Type Null units, his Nichirin blades and ores, the blue spider lily plants, the drugs and poisons he had created, their tree house, and even Akira's bike. He wasn't leaving any of it behind.
Erika blinked. "You're taking all of that? The drugs and poisons, too? What if demons come back one day?"
"I'm leaving all my notes here," Akira replied. "And the blueprints for the Type Null units and other things, too. If demons ever come back, they'll be ready."
"I see," Erika said, smiling.
They took one last look around the room.
Then, without looking back again, they left.
They went to the garden, where everyone had already gathered.
All of the Demon Slayers were there.
The Hashira.
The swordsmiths.
The Ubayashiki family.
Even Tamayo and Yushiro.
Everyone had come to see them off.
"…Looks like it's time," Akira said quietly.
Akira and Erika stepped forward together.
"Everyone," Akira said, bowing his head slightly.
"Thank you for taking care of us."
Erika bowed beside him. "It's time for us to leave. Goodbye."
The courtyard fell completely still.
Tanjiro was the first to move.
He stepped forward and bowed deeply.
"Thank you. For everything," he said, his voice steady but full of emotion. "I'll never forget what you did for my family."
Nezuko smiled warmly and nodded. "Thank you."
Zenitsu wiped his face dramatically.
"DON'T JUST LEAVE LIKE THIS!" he shouted. "AT LEAST COME BACK TO ATTEND MY MARRIAGE WITH NEZUKO!"
Nezuko turned bright red. "H-Huh?!"
Inosuke crossed his arms.
"NEXT TIME WE FIGHT, I'M WINNING."
Mitsuri suddenly hugged Erika tightly.
"You did so well!" she said brightly. "I'm really proud of you. Take care, okay?"
Erika hugged her back just as tightly.
"Thank you… for everything you taught me."
Kagaya stood with his family, calm and whole beneath the lantern light.
"You gave us an ending," he said gently. "And the chance for a beginning. You will always be welcome here."
Akira nodded once.
"I'll remember this place, and I will be back."
They both reached out their hands, and their Kasugai crows fluttered down.
Rose perched on Erika's arm, tilting her head cutely.
Raven completely bypassed Akira and landed straight on Erika's shoulder.
"Let's go, let's go," it cawed.
Akira stared. "…You traitor."
Erika laughed softly.
They turned back to face everyone.
"…Thank you," Erika said quietly.
"And goodbye," Akira added.
The night sky above them shimmered.
A beam of starry purple light descended silently, bathing them in a gentle glow, like starlight drawn straight from the heavens.
The wind stirred.
Lanterns swayed.
For a moment, Akira and Erika stood there side by side, their crows with them.
Then the light flared.
And when it faded, the space where they had stood was empty.
Only warmth remained.
Everyone stared in silence, awed and a little sad at their friends' departure.
Thanks to Akira and Erika, this world had finally reached the happy ending it deserved. Surely, everyone here would have their happily ever after.
Though, unfortunately, decades later, humans in this world would begin developing superpowers because of the vaccine Akira had created, changing the course of this world's fate in an entirely different way.
But that… was a story for another day.