Renewal Taekwondo in Multiverse

The journey was long but warming. Mori, Shinobu, and Kanae traveled through dense forests, crossed rivers, and traversed mountain paths. At night, Mori would often train while wielding the Fake Yeoui, usually sensing demons lurking in the shadows as well, their eerie eyes watching from the darkness. He didn't tell his sisters about them. Instead, he took matters into his own hands.

Whenever the opportunity arose, Mori hunted them down silently, incapacitating them with his martial arts before stringing them up on trees, leaving them exposed to the morning sun. By dawn, the demons were reduced to ashes, their existence erased before they could pose a threat to his sisters.

After seven days of relentless travel, the group finally reached their destination. As they passed through a large wooden gate, a sprawling mansion with multiple side buildings and vast open spaces came into view. The scent of medicinal herbs filled the air, mingling with the fresh fragrance of blooming flowers.

Mori's sharp eyes scanned the surroundings, taking in every detail.

"So this is the Butterfly Mansion… If I remember correctly, that means we're near the Demon Slayer Corps headquarters," he thought. His stomach grumbled. "Man, I'm starving."

As they walked further in, Shinobu tugged at Kanae's sleeve and tilted her head curiously.

"Sister, where are we?" she asked, her innocent voice carrying through the courtyard.

Kanae simply smiled and continued leading them through the mansion. Eventually, they arrived at a spacious room with wooden flooring and soft cushions surrounding a large couch.

She gestured for them to sit.

Mori plopped down on the couch for a second before bouncing back up.

"I'm hungry! You got any food here, sis?" he asked, rubbing the back of his head sheepishly.

Kanae, who had been smiling gently before, now had a serious expression. She looked at both of them, her eyes filled with concern.

"Mori," she began, "do you remember the grey-skinned man you encountered last time?"

Mori nodded, already knowing where this conversation was going.

"That thing is called a demon," Kanae continued. "Demons are former humans who have lost their sanity and humanity after transforming. They possess supernatural abilities and an insatiable hunger for human flesh."

Shinobu furrowed her brows, struggling to comprehend the gravity of her sister's words. Mori, on the other hand, already knew all of this, so he simply grinned.

"Don't worry, sis," he reassured her, flashing a confident smile. "I won't die that easily."

Kanae sighed, kneeling down and pulling both of them into a warm embrace.

"I love you both so much," she whispered. "I don't want either of you to get involved in this world… but at the same time, I don't want you to die one day because you weren't prepared."

She pulled away slightly, her lavender eyes filled with determination.

"The organization I'm a part of—its sole purpose is to eliminate demons and, ultimately, kill Muzan Kibutsuji, the progenitor of all demons. It's called the Demon Slayer Corps."

Mori and Shinobu listened in silence, absorbing her words.

"I won't force either of you to join, but if you wish to survive in this world… you must grow stronger," Kanae finished.

---

A month passed since Kanae had educated them about demons.

Since then, both Shinobu and Mori had begun their training, each following a different path.

Shinobu often accompanied Kanae on trips to various villages, observing firsthand how her sister fought demons and helped others. She studied her movements, memorized the way she wielded her sword with precision, and absorbed everything like a sponge.

Mori, however, had a different approach.

He spent his days honing his body, refining his martial arts, and pushing his limits with the Imitation Yeoui. Every single day, he performed 10,000 swings with the weapon, training until he collapsed from exhaustion.

Lying on the ground, drenched in sweat, he called out:

"Status!"

---

[Jin Mori]

- Age: 5Y 2M

- Race: Human (???)

- Physique(s): Stone Monkey Body (Upgraded)

- MCoins: 1500

- Skills: Kyokushin Karate (Mastered)

- Items: Letter 1*

- Weapons/Armor: Imitation Yeoui

---

Mori smirked.

"I don't think even Daewi Han could've swung around 10,000 pounds like this," he muttered to himself. "At the very least, I'm stronger than he was at the start of The Three Heavenly Wars with Mori Hui…"

His excitement was short-lived as he realized something.

He needed 5,000 MCoins to unlock the system's shop. And to get that many? He'd have to hunt demons.

Mori looked down at the Imitation Yeoui in his hands, an idea forming in his mind.

"Shrink" he commanded.

The massive stone staff instantly shrunk down to the size of a small pick, no larger than a sewing needle.

It had taken him two whole weeks to figure out how to properly control its power, but now, he intended to use it in his training.

He carefully tucked the tiny Imitation Yeoui into his ear, just like Mori Dan had done in the past.

The moment it rested in place, the full weight of 10,000 pounds pressed onto one side of his body.

Mori gritted his teeth, steadying himself. He concentrated, gradually spreading the weight across his entire body until the immense pressure balanced out.

A slow grin formed on his face.

"Just two months ago, I could barely swing this thing, and now I'm using it to train my whole body… I'm a complete cheat," he chuckled.

To test his adjustments, he performed a series of movements—running, jumping, stretching. His balance remained perfect.

"It doesn't affect my mobility. That's good. But I should get a proper holder for it soon—I can't risk people finding out about its power to shrink and grow."

After an hour of testing his body's adaptation, he returned to the Butterfly Mansion for a well-earned meal.

With his enhanced physique, he needed to eat significantly more than a normal person just to sustain himself. As he sat down to fix himself a large meal, another thought crossed his mind.

"If I remember correctly… those divine pellets Mori ate in the first arc could keep him full for days while also increasing his power," he mused. "Since I have the same Stone Monkey Body, I should be able to eat them too, right?"

A smirk formed on his lips.

"I need to unlock the shop soon."

Finishing his meal, Mori moved to the meditation room, sitting cross-legged as he closed his eyes.

This was his routine now:

- Wake up at 6 AM.

- Train until 12 PM.

- Meditate until 3 PM.

- Help around the mansion until everyone else fell asleep.

It was grueling, exhausting, and at times monotonous.

But Mori wouldn't stop.

Not until he became the strongest especially to save his sisters in the future from dying to Doma, The Upper 2nd Kizuki.

Another 6 months passed by quickly, making Mori almost 6 years old.