A Hanma in JJK

Premise: Yuichiro dies and gets reincarnated in the world of JJK as Riko Amanai's younger brother with a cursed technique that is kinda OP.

......

"Hmmm...What a reckless child that red-haired demon is. Still, I think he's technically the strongest now," A wisened older man who stood at around 6'0 thought as he ran his hand through his greying hair, "well...apart from me. I'm now his final opponent. It's a shame he didn't inherit my demon mind but I'm not one to fight my own son so..." 

Yuichiro Hanma climbed onto his bed and faced the ceiling before taking in a deep breath and falling asleep on command. His breath stopped not a minute later. However, in the space of that minute, Yuichiro was simulating his final great battle. His body convulsed and a stream of blood escaped from his lips.

.....

In his mind-scape, Yuichiro sighed, "Let's increase the immersion to...hmm... 500% should do the job?"

Before long, a group of 5 nukes fell from the sky. Yuichiro smiled as he leapt into the air, flexing the muscles on his back into the shape of a demonic face. The first nuke exploded as he punched it, covering him in a mushroom cloud of radiation...

A slightly injured Yuichiro used the force behind the explosion to increase his upward trajectory, opening his arms out to grab the next two nukes.

Forcing them into each other, the heat from their combination began to melt his outer and second layers of skin, his vision now completely dark. Yuichiro began relying on his other senses to locate the other two. Launching himself off of one of them, he reached out and grabbed the final one with his arms in an axe-holding manner. Throwing it down, he thrust it down towards the ground.

Boom!

Crash!

Yuichiro Hanma, the strongest monster ever, crashed to the floor, with no skin left on his body, his lungs deflated, unable to draw breath anymore. Taking his final moment to appreciate what had happened, Yuichiro mentally sighed,

'Even in death...I still can't lose? I Still can't remove the burden of victory and feel the peace... of failure?'

...

"Yes, throughout heaven and earth...I decree this soul an honoured one," An omniversal being spoke as it held Yuichiro's soul in one of its many appendages. 

"Do not give up on life yet, O' Honored Strongest of mine. Simply walk the path you believe to be true and never... never forget that only the strong can be truly kind," The being seemed to somehow...smile? as those words reverberated through Yuichiro's soul. 

"Now off you go O' honoured one, blessed be your reincarnation's ability..." It said as Yuichiro felt something being added to his soul before he got sucked towards another realm. After the disappearance of Yuichiro's soul, the being began to contemplate,

"A fragment of a great demon god huh...  A truly fitting ability if he can learn to control it." 

.....

"Oh honey, look at his cute face...our little Goro is so cuuuute. I'm sure Riko is going to love her little brother," A father holding his baby smiled as he handed his baby back to his wife. This was one of the happiest moments in their lives, the couple both had smiles on their faces. Albeit, the mother seemed extremely tired and so fell asleep. 

The father smiled as he took the child from his wife, kissing her forehead before he began to rock his child to sleep, 'this is perfect...'

However, Goro...was extremely confused.

"A new life? What an interesting development..." Goro said, his previous life as Yuichiro Hanma played on his mind. Does he let go? Or does he hold onto those experiences? 

Thinking too hard on the matter, he got tired and seemed to drift off to sleep. 

...

A month later.

'Past life, new life, what does it matter, all it should do is serve to further my power. After all, that's the only way I'll move forward. If I get hung up on what to do, I won't even be able to take a step in the right direction. So I'll use everything I learned in my past life to rise to the top again,' Goro Amanai thought. He was rapidly approaching his first birthday with his loving family. He'd been alive for 10 months. Even though he couldn't train properly, he was still doing girl pushups when no one was watching him.  Even as a baby, he was trying to hit every major muscle group, using the bars on his cradle to hold himself up when doing squats. However, as with all things, there had to be a spanner in the works.

"Riko, you stay here with your brother okay? We're just going out to- to get groceries," their mother spoke with a shaky voice which caused the little girl to nod. This didn't go unnoticed as Goro from the cradle in the living room saw their expressions. His stomach sank as he decided to cry,

"I Wuv you. Ma-ma, Da-Da?"

This caused his parents to turn around and smile at their child, tears threatening to escape from their eyes,

"We, we love you too Goro and my little Riko, Grow up to be strong okay?" 

His father ruffled Riko's hair which caused her to pout. He pulled his hat down to cover his face before grabbing his wife's shoulder,

"Come on it's time to go honey." 

This caused Goro's eyes to widen, he knew the tone of those words all too well. His parents had closed and locked the door.

'No...Not like this. All I wanted was the peace of the weak. Not the weakness of inability to act in the first place,' Goro said as he began trying to jump out of his cradle. Alas, he was still a baby. 

After being unable to jump out of it, he took a more indirect approach, he began rocking in the cradle. This caused the cradle to rock with him before...

Crash!

The cradle tipped over and allowed Goro to escape. His sister's eyes widened, and Riko was gobsmacked. Her brother had always just been a cute baby to her before today.

"Goro, stoppp, Mum and Dad said we need to stay in the house whilst they go grocery shopping," She said as she tried to run after and then pick up her little brother. 

Unfortunately, he had gotten to their cat flap too quickly and crawled straight out onto the steps leading to their front door. Craning his neck to the direction of the road, he noticed their car had disappeared. 

Goro's eyes widened as an uncontrollable fury hid in his burning red eyes, he had just managed to control it. However, his eyes glowed a volcanic-orange colour as he crawled back into the house to find a crying Riko.

"Why, why did you leave me as well Goro?" Riko whispered as she curled up in a ball. 

"Me Sowwy Riko, I wuv you. I wuv mama an dada too. I no want them to go," Goro spoke in a broken baby. However, this was enough for Riko to understand. Her face brightened at that as she realised her brother had spoken his first words to her. This caused her to run over to her little brother and pick him up. Giving him some kisses on his forehead, she noted how heavy he was.

"Why are you so fat even though you don't look it?" Riko asked him as if expecting him to answer at the level of an adult. This question caused Goro to giggle cutely, allowing him to get his mind off of what had just happened, even if only a little.

Holding Goro on her lap, their front door opened causing both of their eyes to shine with a hopeful light. However, to their disappointment, a duo of men in black suits entered the house. Goro waited with patience to hear what these people were going to say, however, his patience was drawing thin.

"Hi there kids, my name's Masamichi. I hope we haven't interrupted 

your play but I've come with some bad news and some good news," The young man who wore black sunglasses spoke as he crouched to the height of the children. 

"Your parents seem to have passed away. They did love you though, it seems that it's just you two left together now, I'm really sorry for your losses."

Goro's fury seemed to subside as, at least the inspector was willing to tell him the truth, but he had questions that WILL be answered when he grows up a bit. Goro pretended to have gotten tired from that exertion yet he did actually fall asleep,

'I hate being a baby... and I hate the number ten now...'

....

"Phew, at least the baby's asleep," Masamichi's accomplice spoke as they discussed the results of this mission. Whilst the accomplice gave his thoughts, Masamichi lit a cigarette. Wafting into the Baby's nose, Goro woke slightly and just listened into their conversation. Taking a deep breath,

"Well it's not our role to interfere now, we just have to deliver the girl to the relevant authorities and that's our duty complete," Masamichi spoke with straight-forwardness.

"What about the boy?" The other spoke, "I know it didn't produce a positive result as a star plasma vessel but that thing's cursed energy was-"

"Don't worry, I'm retiring from active duty, Tokyo's Jujutsu High seems to have a teacher opening," Masamichi spoke as he thought about what he could do with the child, "I'll take HIM with me, I'll raise HIM. Remember Takeru, he's still a human and we should treat the baby as such." 

Goro smiled internally, this inspector seemed like a nice guy.

A while later, Riko seemed sad to say goodbye to her brother but she smiled, after all, it was not like it was going to be the last time she saw him. Goro insisted on remaining with his sister but it's not like he could threaten to kill them. After all, he was still a baby and if he spoke those words then he'd be investigated.

Goro didn't even bother to ask what the energy they were talking about was, he could infer that it was some sort of supernatural fuel for abilities. He would claim everything once he's older.

....

Seven years later,

"Goro-kun, Dinner tiiiime!" A middle-aged Masamichi yelled out into the forests of Tokyo Jujutsu High. 

In the forest, an eight-year-old kid with dark brown hair and blue eyes was focused intently on striking a thick, large oak tree. Hearing the echoing shout of his adoptive father, Goro began to speed up his training. 

*Crick*

*Crack*

Goro's punches and kicks began to speed up to the point that they seemed like whips, even to a jujutsu sorcerer's eyes, a black crackle forming around his fist...

*Boom!*

The large oak tree collapsed with a large thud, releasing a black arc of lightning, causing the sweating Goro to smile,

"Another physical milestone... Let's try it all out in combination... with my innate technique..."

Clenching his fists, he flexed the muscles on his back. The face of a demonic entity was formed from the muscles on his back. His cursed energy suddenly flared a black and green colour, covering his fist in it, he began thinking "If that was what I can do at this age..." 

Spinning backwards and moulding his innate technique to cover his body, he phased through 200 metres of woodland trees and shrubbery before delivering a spinning back elbow to a nearby tree.

BOOM! 

The tree wasn't just destroyed, it was shattered into pieces that continued with great momentum, puncturing holes in the trees behind for at least 300 hundred metres as if they were bullets.

"...[Liberation] is busted..." 

"Time to go Home," Goro thought as he picked up the intact wooden tree and carried it on his shoulder, relaxing his back muscles. Covering his body in cursed energy he increased his speed as he began running home, charging through any trees that came into view. All of them remained intact.

"Daaad, I got more wood for the storehouse," Goro spoke as he saw the familiar face of his adoptive father, Masamichi Yaga. However, his father had a relatively serious face as he rubbed his son's head,

"I heard that bang out there... You used Black Flash again didn't you?"

Goro sweatdropped as he shrugged, "What can I say... I just enjoy beating the shit out of things..." 

Masamichi sighed as he held his forehead, 

"You know. Some day that mouth of yours is going to get you into big trouble, and I might not be there to help you out you little rascal."

Goro shrugged nonchalantly,

"If I ever get into a problem because of it, trust me, it'll be the other guy you have to help out." 

Masamichi shrugged, "Well with that innate technique of yours son, I think that's probably true but you have to remember to be humble about it... Anyway, remember to chop up the wood before you store it. Your sister's coming today right?"

Goro got to see his sister twice a month. It was what his adoptive dad had managed to negotiate with the higher-ups, 

'Once I get to their age, that's going to change. Only my stature and age are limiting me right now.'

"Okay, well I'll be dealing with an important guest whilst you play with her so I trust you to be responsible in the house. She'll be dropped off at the same place as she usually is, I trust you to be strong enough if anything happens," Masamichi says as he rubs Goro's hair. Goro nods, he allows his foster father to act close to him as he has only ever helped him, for that, Goro thanks him by acting as close to a child as possible.

Goro nodded, 

"Sure, I'll stay in the house with Riko, Enjoy your ass-kissing session, Dad."

Boom!

Goro received a thump to his head, "Ow, what if I become retarded because of that hit?"

"I'm hoping so, maybe you'll forget how to use that smartass mouth of yours," Masamichi said as he closed the door and waved his son goodbye. 

Stepping outside, Masamichi lit a cigarette and inhaled deeply with a sigh,

"That kid is going to be the death of me one day." 

Puff.

Exhaling, he glanced back through the window to see his adopted son chilling on the sofa before smiling and walking away.

...

A black SUV drove far and high into the mountains. Naturally, this SUV contained an elder of the Gojo clan along with their security in the back seats. A lot of trees surrounded Tokyo Jujutsu High to further obscure the location.

The elder sighed before the car pulled to a stop,

"We've arrived Master Nagato. It seems that Principal Saionji isn't present but the teachers are." 

Nagato shook his head, this was an insult to their Gojo family and himself. His eyes reflected a furious disposition, 

'Do they think the Gojo family are pushovers? In the next ten years, we're going to be the strongest family with Satoru's existence. They should be praying to get on our good side, Gojo is visiting the other school right now...'

"Welcome to Tokyo Jujutsu High, Elder Nagato of the Gojo Family," Masamichi greeted the visiting group. He felt a heavy cursed energy getting released and burden all of their shoulders. 

"What is the meaning of this Misamichi Yaga?" The elder spoke as his cursed energy pressed on the shoulders of the teachers. As they stood gritting their teeth, Nagato continued, "If you intend to offend the Gojo family, I hope those little cursed corpses of yours can protect you."

Unaffected, Masamichi smiled as he began explaining why the principal wasn't there,

"Unfortunately, Principal Saionji can't be here to greet you since she's in her operating theatre during a critical operation." 

This caused an aide to tap the elder on the shoulder, indicating he should calm down. Even though Nagato didn't want to let this matter go, he couldn't ignore Masamichi's words. This caused him to retract his cursed energy as he nodded. 

Masamichi snorted internally with an internal gloat,

'You call that cursed energy? The old geezers like you can't even compare to my son. As long as I keep him well hidden from you old foxes, he'll become one of the strongest as well.'

"Elder Nagato, it's an honour to have you look around the school. I'll take

you on a tour, hopefully, we can provide you good company," Misamichi spoke respectfully.

...

"After all, I'm the strongest monste-" 

Boom!

Goro had his head thumped again. 

"Sisssss! Not you as well?!" Goro fake cried out loud as he felt injusticed at being hit twice today. He was now in his living room, playing a game of Monopoly with her before being hit.

"Hmm, yes, it's much quieter. If I didn't hit you, you'd probably come up with some stupid phrase like 'I'm the strongest ever,' blah blah," Riko said miming the way her younger brother would flex his muscles.

Goro just pouted and said nothing, 'she might be right. She's probably right... She's right, I definitely was about to say that.'

"So I'll take that rent for Hachiko Square," Goro grinned cheekily as he held his hand out for the pay, "Cough up 30." 

Riko glared at him as she handed over the right amount. 

"Money moves the world big sis, no point in being sour, hehe," Goro said as he counted the money she handed over to him.

"I swear, if this was an anime, you'd probably have money signs in your eyes at this point..." Riko spoke as she began to roll her dice as well.

"Probably," Goro nodded in agreement as he waited with bated breath for the dice to land. 

It was a 6.

Riko slammed her hands on the table,

"I don't want to play this game anymore."

"Hehehe, off to prison you go, big sis," Goro said as he moved her piece to the prison square on the board.

"I feel like I'm already in it sometimes, Goro..." Riko said as she laid back on the sofa. Goro's eyes narrowed for a moment,

"All I need is a name, their address and their route to work from home." 

Riko laughed a bit before smacking her little brother on the arm,

"I don't think I like the idea of my little brother becoming a world-wanted assassin, Goro. It was a good joke though." 

Goro scooted closer to his older sister before giving her a hug, she sighed,

"You know, our lives became so much bigger than ourselves ever since we got involved with this side of the world, Goro." 

Goro shook his head in response,

"I don't think so. I'm still doing what I want, within limits. The day they get too greedy, I'll raze their ho-"

Thump!

"Goro, Please don't speak like that. Ever. Again. You're a good person deep down, you're still my little brother," Riko said as she rubbed her fist, "But How is your head so robust, my fist is starting to hurt now..."

"I have an innate cursed technique."

Riko's eyes widened as she reeled back in shock. She knew her brother had a lot of cursed energy.... but this was a big shock to her nonetheless.

"And..."

"It lets me negate anything physical," Goro confirmed, "I called it Liberation." 

Riko laughed at that, causing Goro to look at her in confusion,

"Oh, it's nothing, I just... pfft. I think it sounds very similar to another ability I've heard of before."

Goro deadpanned,

"Just because it starts with an L doesn't mean it's like that Loser teen's Limitless."

Riko nodded, holding back a cheeky laugh.

"Dad said the same thing, I don't think it sounds the same at all. And Mine's better anyway. It's stronger," Goro said patting his chest.

Riko nodded with a teasing gaze, 

"Suuuuure. Because a guy who might be able to negate a punch could tussle with a family who can literally control space." 

Goro rolled his eyes before they sharpened, he felt his innate technique activating causing his gaze to dart between the windows.

Boom!

Time seemed to slow down in Goro's eyes as he noticed a black