When they arrived, Tanjiro had to hold back a raging Hayami Agatsuma.

"What are you doing, Dad? Let me at those incompetent bastards! It's time they learned what I can do before they assume I'm unworthy, goddammit!"

"We can't allow you to do that," Tanjiro said. "These guys are in a position of utmost respect."

"I don't give a shit! Let me at 'em, dammit! Say I'm not ready for missions 'til my next birthday, eh? Well, frick you!" Hayami shouted.

She broke free from Tanjiro's strong arms, her katana raised as she raced towards each one of the Hashira. But before she could attack, she was stopped by a hand of someone who was not that much older than her.

"Don't get over your head," the boy said with an expression that seemed apathetic.

"Who the frick are you!?" Hayami said, trying to fight his hand. "I want answers!"

"Simmer down," he said. "My name is Muichiro Tokito. I've heard you're twelve, am I correct?"

"Damn right I am!" Hayami said. "And I can show all of you bastards how strong I am! How capable of going on a mission I am if you just let me demonstrate, dammit!"

"I'm two years older than you. You say you just started learning and training when you were 10 up until 12 years of age?" Muichiro said. "You're inexperienced."

"That's why I came here to train to become a Hashira! I have what it takes!" Hayami said, flailing around in anger.

"Put away your sword. That's not gonna get you anywhere," he said.

The Demon Slayer Master, Kagaya Ubuyashiki, appeared. "Another day, another era! Taisho has come and gone and now we mark the beginning of the Showa era! With the growing amount of demons being defeated, you may think that the need for Demon Slayers is inevident. But let me tell you this: it isn't. Because each and every one of you standing here right now is living evidence that we have come so far and that we exist for the sole purpose of protecting everyday humans against the demons of the world. And I thank you for that.

We also have a new member of the Demon Slayer Corps joining us today, being the daughter of Demon Slayer Zenitsu Agatsuma and demon sister of Demon Slayer Tanjiro Kamado, Nezuko Kamado."

He gestured for Hayami to come forward. "Please welcome… Hayami Agatsuma, the youngest member of the Demon Slayer Corps!"

She smiled awkwardly as all of the Hashira clapped for her. She did not know whether to be excited or embarrassed, but she seemed to show embarrassment much more. Blushing, Hayami said, "Thank you. I am deeply honored, Oyakata-sama. But I cannot accept this until I apologize for my actions towards the Hashira."

Turning towards the Hashira, her blush faded and her face looked a lot more serious and genuinely regretful. "I apologize for the way I acted coming into the Demon Slayer Corps today. It was stupid and really immature of me to act in such a way, especially in the presence of such Demon Slayers held in such high power. I couldn't control my actions, and I know this is a piss-poor excuse, but I cannot fully regulate my emotions quite yet. I'm still learning along with everyone else, and I would appreciate it if all of you were patient with me. As you can see, I am ready to show you my skills and make you see how I am worthy of becoming a Demon Slayer, if you would so allow."

Tengen approached Hayami. "I'm intrigued," he said. "Let's see what you can do, kid."

Hayami smiled. "I won't fail to impress you, Hashira-sama," she said.

Tanjiro whispered in her ear. "That's Tengen, by the way. He's a flashy and cocky son of a bitch who declares he's a god."

Hayami laughed out loud. "A god, you say? I highly doubt it," said Hayami.

"Let's see who's the flashiest, shall we?" Tengen said. He eyed Zenitsu. "I've heard you've gotten married to both the demon and Tanjiro."

"Sure have," said Zenitsu. "And it's the best fucking decision I've made in my life."

"Happen to be polyamorous too, Zenitsu?" Tengen said. "Well, we have something in common, don't we know?"

"Polysexual, polyamorous. Whatever the hell you wanna call it, I don't care," Zenitsu said.

"Oh OK then," Tengen said. "Now let's see who's the flashiest, shall we?" He said this to Hayami.

"This is not a battle of flamboyance, Tengen-sama. It's a battle of worth," Hayami said. "And if you cannot accept that, I will gladly take on that guy over there!"

Tanjiro and Zenitsu tried to get her attention, but it did not work.

She grinned mischievously.

"That's Sanemi," Tanjiro whispered. "I'd not fight him if I were you. He tried to kill Nezuko and then proceeded to stab himself to 'prove' that Nezuko will 'break' and bite him. But when she refused, he still didn't accept me and Nezuko."

"That bitch!" Hayami swore in a whisper response.

"Yeah. That's why I'd take my precautions with him," Tanjiro said.

"That just makes me wanna fight him even more!" Hayami said with an overconfident cackle. "Bring it on, Sanemi-sama! I will show you my worth and you will accept me as a Hashira when I defeat you!"

Sanemi smirked. "Tough words for a kid. Do you really think you can defeat me?" Sanemi said.

"I don't know, but I can try," Hayami said.

Sanemi laughed. "You're all talk, kid."

Hayami grasped her sword as tight as she could. "Try me," she said.

"Then get ready for a death wish," Sanemi said. "That blasted demon didn't stand a fucking chance! I could've sworn she'd break if she had the audacity to, that goddamn bitch!"

Hayami's teeth clenched, her sword raised. She turned into a completely different person as she got pissed. "Insult my mother one more fucking time and I'll slice you right open!" she shouted. "I will not hesitate. I will kill you. So don't fuck with me, you got it?"

Her speech just fueled Sanemi. "Nice speech, but can you live up to it?" Sanemi said. "You did say if you managed to defeat me, you'd be named Hashira. Let's rephrase that. If I sense that your power is strong enough, I will consider you to Oyakata-sama."

Hayami smiled with determination in her eyes. "Challenge… accepted," she said.

Sanemi laughed, unsheathing his sword. "Let's get this motherfucking fight started, Hayami Agatsuma."

He smiled. "Sixth Form: Black Wind Mountain Mist!" he called out.

A tornado of slashes violently came in Hayami's direction. She did not have much time to think, so she counterattacked with Frozen Tundra. But in her disbelief, Sanemi dodged.

Grasping his sword, he assumed the movements and footing of the second form, Claws, Purifying Wind. "Take this!" Sanemi said in a battle cry. "Second Form: Claws, Purifying Wind!"

Hayami ran in between each slash to avoid it, jumping up in the air and flipping down onto the ground as she managed to attack Sanemi from behind. "Eleventh Form!" she said, spinning in midair. "Breaking Avalanche!" She violently struck Sanemi in the back with a huge splash of blood splashing onto the battlefield.

Damn, she's fast, he thought. Sanemi winced, grabbing his back, which had several bloody gashes resulting from the blow. He could not stop the bleeding, but he continued to fight despite his injuries.

Sanemi let out a chuckle. "Great job. You landed a hit on me," he said. "But I won't let a twelve-year-old girl like you bring me down!"

As he moved, the wounds in his back continued to tear open as blood spilled on the battlefield. But it did not bother him. He was a motherfucking Hashira, one of the strongest of the strongest Demon Slayers on this motherfucking Earth, and he was not gonna let this stop him. Not now. Not when he got this far.

"Ninth Form: Idaten Typhoon!" Sanemi said, backflipping into the air.

But as soon as he began attacking, Hayami called out, "Too fast, Sanemi-sama. Shield of Impalement!" Instantly, a shield of ice surrounded her and impaled Sanemi in the stomach.

Sanemi fell to the ground, gripping his bleeding abdomen in pain. He sat up, coughing up blood. Sanemi grabbed his sword and stood up, wiping the blood off of his face. "Nice move, Hayami. But can you take this?" He jumped up in the air and violently swung his blade, creating a gust of gale-force wind. "Seventh Form: Gale, Sudden Gusts!"

This time Hayami had no time to act, but when she did, she was already bleeding from a hit to the head. The blood from her head dropped down to her face and onto her Demon Slayer Uniform, staining it blood red. "Fuck," she swore under her breath. But she did not let this stop here. Determined, Hayami let out a battle cry, racing towards Sanemi with her sword grasped in her hand. There was no way in hell she would let it go now.

"Fourth Form: Showers of Hail!" she cried. She lunged towards Sanemi, who got hit by big pieces of hail, giving the Wind Hashira a bad ice burn.

Sanemi smiled. "First Form: Dust Whirlwind Cutter!" he called out.

Jumping out of the way just in time, Hayami dodged and counterattacked with her final form. "Twelfth Form: Ice Dragon!" she shouted.

There was no avoiding this attack. Sanemi fell to the ground, unable to get up. After using all of her strength, Hayami also fell unconscious. But unlike before, she recovered in a matter of minutes. Both bleeding, Hayami pointed her sword at Sanemi. "I win," she said.

She put her sword down to her side and closed her eyes. "Ninth Form: Ice Healing, Modification: Heal All!"

Instantly, all of their wounds were healed.

"You didn't have to do that," Sanemi said. "You didn't have to heal me."

"I did it because I'm nice," Hayami said. "And because someone told me that all Hashira deserve utmost respect."

"Well, I am eternally grateful," he said. "But I will still not get over how much sheer power you have! It's incredible!"

Hayami grinned cockily. "I do, don't I?" she said, returning her katana to its sheath and putting it in the resting place of her white belt.

The Master came up to Hayami and held her hands up in the air. "For your beautiful attacks and incredible power, you are named the Ice Hashira at just twelve years old."

"Oh my gosh! Oh my gosh! Oh my gosh! This is a dream come true!" Hayami exclaimed. She went to hug all of the Hashira, then Tanjiro, Zenitsu, and Nezuko. "I wouldn't have gotten so far without the help of you three," she said with tears in her eyes. "You're my family."

Tanjiro, Zenitsu, and Nezuko cried as well, hugging Hayami back. "And we're proud of you, Hayami. Don't you ever forget that."

Inosuke held out his arms. "Don't leave me hangin', kid," he said.

"Ah, what the hell?" Hayami said. She ran towards Inosuke and gave him a big hug. "Without you, Dad Tanjiro and Dad wouldn't have had sex with each other!"

Tanjiro and Zenitsu blushed like tomatoes at each other. They turned away from each other in embarrassment. When Nezuko jumped in between them, Zenitsu blushed even more. Tanjiro just smiled at his sister, embracing her in brotherly love. Hayami and Inosuke joined them as Zenitsu kissed both Nezuko and Tanjiro on the lips.

It was the end of a story, but just the beginning for Hayami's adventures as the new Ice Hashira.