Redemption

1.

Kokushibo took a moment to regather his emotionless persona, before he appeared in the Infinity Castle.

The rest of the upper moons were there, but none knew why.

"There is a new hashira out there, someone care to explain who exactly she is?"

Gyokko spoke up, though Kokushibo mainly drowned him out.

In his past life he'd cared little for upper rank five, and now, well, that hadn't changed.

"No one knows sir, we don't even know her breathing style."

Muzan just nodded along.

"I think it best to send the top three upper moons to search for her."

Kokushibo mentally frowned, thankful he'd found Tamayo after months of searching and gotten out from under Muzan's control.

Let's see, Akaza could be redeemed, he hoped.

But Douma, well, that was 50/50, and Kokushibo never trusted chance.

Sure Douma didn't care about Muzan, nor Muzan him, but that didn't mean he wouldn't just rat him out.

In any case, he found himself being sent out into the middle of the woods to find that hashira.

...

He heard screams, but, they were more of rage than pain.

He rushed to find the source, stumbling across a house.

A young boy, with long hair who could only be eleven, was fighting a demon.

Wait, not just any boy...

...

The mist hashira, only before he was a demon slayer.

He remembered slicing him in half in the past life, and he wasn't going to be such a fool this time.

Muzan Kibutsuji be damned.

He rushed in, slicing off the demon's head in a instant.

The demon in question disintegrated, and he turned to look down at his descendant.

"What is your name young one?"

He couldn't raise suspicion by revealing he already knew.

The boy just gulped.

"M-Muichiro."

"My name is Kokushibo. I am the upper moon one demon, but I am not here to harm anyone."

Granted he still killed and ate people, but he made sure everyone he killed were those who were bad people.

"Why were you screaming?"

"My...my brother Yuichiro, he's hurt really bad."

He pointed to the house.

Kokushibo went over and entered, finding the other boy, the twin boy, on the floor bleeding out, his arm sliced off.

He crouched down.

"You are Yuichiro." Not a question.

There was a sadness in his tone.

In a brief moment, he imagined if this had been him and Yoriichi.

Thank the gods he'd repaired that relationship in this timeline. The two got along good, and he never hated Yoriichi, he'd mostly tease him in a passive aggressive manner, which Yoriichi just returned.

Damn his pain in the ass brother.

His brother died of old age, so he lived a good and long life. The last time they saw each other, Kokushibo snuck away from Muzan to see him on his death bed.

Yoriichi had wished for him to become human once more, and he'd promised his brother he would.

And he would keep it.

"P-please...t-tak...take care of M-Muichiro...he's too good for...this world, so...pure. I was the bad one, I...deserve this punishment of death. I...was...unworthy..."

The boy passed after that, leaving a sobbing and broken Muichiro.

Okay, he was not that great with parenting, despite Yoriichi saying otherwise, but he'd try his best to watch after his descendant.

He was not going to harm him this time, nor would he harm any of the hashiras.

This night, Kokushibo set his mind to one thing...

Bringing the downfall of Muzan Kibutsuji.

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"Are you hungry?"

They were in a cave now, having buried Yuichiro outside the Tokito family house.

They payed their respects and then left, until they found this cave.

"Not really." Muichiro responded blankly.

Kokushibo put the plate in front of him, not taking no for an answer.

"Eat young Muichiro, you require your strength, especially if I'm to teach you."

Muichiro just went along with it, giving in and eating everything on his plate.

"Teach me?"

"Yes, I will teach you how to be a demon slayer."

Muichiro perked up as best as he could at that and accepted.

The next morning, he made Muichiro eat breakfast, before giving him a makeshift wooden sword to train with.

They started slow, Kokushibo knew he had a lot of potential, but best not to push the boy that much yet.

Muichiro had no issue with the fake sword, but his movements were uncoordinated and below amateurish.

Later that evening, they ended the first session, and Kokushibo planned out for the next day.

Tomorrow they'd start on his breathing, because he had to master this before anything else.

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That night, Kokushibo awoke to snapping branches, and went on guard, fearing other demons.

But when he checked outside, he looked down to the right to see the most beautiful pair of light purple eyes he'd ever seen.

This woman was absolutely beautiful.

She noticed he was a demon and went to grab her sword, but he made a surrendering gesture.

"Calm down slayer, unlike most demons, I mean no harm."

"How can I trust you?" She asked in such a light, perfect, and soothing voice.

Then she saw the kanji in his eyes, and he shook his head.

"If my intention was to harm you, I would have already done so."

She nodded slowly, though remained on guard understandably.

"Any other demon would be out hunting slayers or citizens." She pointed out.

"I'm here with a young boy, Muichiro. He lost his brother to a demon attack last night, and so I am looking after him until I feel he can be on his own."

The young woman seemed sympathetic.

"I can understand his pain, losing a sibling is never easy."

"I know." He added with a sigh, which surprised her.

"You had a sibling?"

"A brother, he died of old age, but I was there with him as he passed."

She made an 'oh' sound at that.

"I'm sorry. I lost one of my sisters to upper moon two." She said.

Mm, then Douma was a definite no now.

"My apologies..." Then he recalled, "I'm sorry, I'm Kokushibo."

She smiled very slightly, a smile that brightened his world.

"Mayumi Kocho."

*This is not all that great a story, lol, but I hope you find it okay at least.