Into the Hunter x Hunter world with Jujutsu Kaisen System

After thirty minutes had passed, Sachiko headed back to the garden to spar with Gon.

"Sachiko san, you're here!" Gon looked so excited just to spar with her.

Sachiko nodded as she stopped using Ten, "So, let's start. I won't be using Nen but don't think I can't beat you up without it."

Gon even looked more determined at that.

He charged towards Sachiko and tried to hit her but she easily dodged them and kicked him away. He let out a pained groan before charging towards her again, only to change directions at the last moment and tried to catch her off-guard from above.

However, with her knowing that Gon likes to do that quite a lot, Sachiko caught him with her hands. Now that Gon had also trained physically, he was stronger than before. But, for some reason, Sachiko wasn't pushed away or more like she didn't feel the impact did much damage to her.

'She's strong, even without Nen!' Killua thought as he watched the spar.

Meanwhile, Sachiko was a bit puzzled.

Wasn't she supposed to be only stronger than ordinary people by twenty times? Ordinary people should only be able to push at most 0.05 tons and twenty times that is about 1 ton.

After training, Gon was now supposed to be able to push about 1.5 tons according to Killua. So, how was she stronger than Gon at this point?

Sachiko initially thought she would have to rely on cursed energy to beat Gon up but now she wasn't using cursed energy and yet somehow she was just physically stronger than Gon?

'System? How do you measure ordinary human strength again?'

[System measures average human strength by the average strength of non-user humans host associate with.]

'Wait, what? As in Killua, Gon, Kurapika and Leorio?'

[That is the case because host has only been close to them so System could only take their strengths as reference.]

'That's obviously a freaking lie. I get a feeling you're making me more overpowered on purpose.' Sachiko thought.

[It's your imagination, host.]

'....It's not!' Sachiko retorted. Well, not that she disliked having more power. As long as it's not disadvantageous to her, she didn't care much.

'But, how did I not kill those guys at Heavens Arena then?'

If she was twenty times stronger than average strength of Killua, Gon, Kurapika and Leorio, she could've easily killed ordinary humans with a kick.

[Host didn't use your full strength against them and they suffered internal injuries and died a few minutes later, host.]

'Oh..makes sense.' Sachiko nodded, things were making a bit more sense. 'Sucks for those guys though. Well, not that I care much.'

With her newfound answer, Sachiko turned her attention back to Gon, controlling her own strength.

Seeing he was caught by Sachiko, Gon tried to kick away but Sachiko threw him to the distance again.

With a few fractures and bruises, Gon got up and started to fight her again.

"You're all roughed up, are you sure you still want to fight?" Sachiko asked.

"It's okay, I can still stand!" Gon said with a determined Shounen MC look and Sachiko was annoyed by the look.

'Ah..that's right, Shounen MCs never know how to give up, do they? Even if it's a meaningless fight, they all get fired up and determined. Typical.' She thought.

"Alright, I guess I'll beat you up a bit more." Sachiko said as she kept kicking and throwing Gon away. She had to control her strength in the process so that the stubborn Shounen MC wouldn't die yet.

"More!" Gon kept getting up and charged towards her even though it wasn't making any difference except his increasing injuries.

'Is he a masochist?' That thought even crossed her mind. 'Am I sadist then? Because I somehow enjoy beating the crap out of people?'

Okay, that sounded a bit wrong.

She didn't want to resemble the creepy clown.

'But, seriously, Gon here knows no limits to his stupidity. He kept getting hit and muttering how he's getting stronger just because I cut him some slack and let him hit me a few times.'

Sachiko had to knock him out at some point so that the stubborn kid wouldn't actually die.

'I'm so sending him away after teaching him Nen basics.' Sachiko told herself.

"Alright, Gon's knocked out. I'm the winner." Sachiko announced as Killua stood, a bit taken aback.

"Oi, eyepatch lady, how're you this strong if you're not using Nen?" Killua asked after a while.

"Well, aren't you pretty strong for a non user? How'd you get strong?" Sachiko hummed and asked.

"Of course, I was put through a hellish training since birth." Killua replied.

"There you have it! I train!" Sachiko said in a cheerful voice. "Now how about we spar for a while?"

Killua stared at her for a while but shook his head in the end, "I'll not fight a battle I can't win."

"Alright, just know you don't have to beat yourself up for it. Don't let anyone else belittle your thoughts, okay?" She told him as she patted his head. "Picking your battles is nothing to be ashamed of and there is nothing wrong with it as long as it is done so in your own will."

Killua's expression changed a bit at that as he reflected on his conversation with Illumi.

"Don't let his words get to you, Killua. You're free to live a life you want to and make your own choices. There's nothing wrong with that."

"Can I really? I couldn't fight you even if it was a spar and I doubt I could've fought my brother even if he threatens me with Gon's life or yours."

"I told you it's fine to pick your own battles as long as that's in your own will. But, if you really want to prove your brother wrong, I have an advice for you." Sachiko said as she put her hand on his shoulder, "You just have to become stronger. Be stronger than Illumi and you won't have to worry about his threats or not being able to fight a battle you can't win."

"Be stronger than Illumi?" Killua repeated, his eyes burning with desire.

"That's right, it's that simple. If you become stronger than them, you don't have to be scared of him anymore." Sachiko told him.

Killua was silent for some time before his eyes burned with desire, "Eyepatch lady, I want to become stronger. I want to surpass my brother and my family. Can you teach me nen?"

Sachiko's lips curled up into a smile, "You bet I will, kiddo."

------------------------------

After Killua sent Gon back to his room, Sachiko called him to a spare room. She had already set up a whiteboard and some desks to give the atmosphere of a classroom.

While she hated classrooms, that was only true when she wasn't allowed to boss around and do things her way. Now that she was in charge, she would naturally make use of the opportunity to boss around.

"Huh? Why does this place look like a class?" Killua muttered.

"Alright, everyone. Take your seats. Today, I'll introduce you to the sacred information which is 'Nen'!"

At Sachiko's rather dramatic introduction, Killua blinked and sat down on one of the chairs. "Isn't it just me? Why are you talking as if you're teaching a class?"

"Shush, Killua. We don't talk about that here."

"We don't?" Killua repeated.

"Yes, and now listen to my awesome introduction on Nen." Sachiko said in a more dramatic manner. "Now, Nen is a technique that allows a living being to use and manipulate their own life energy which is also known as aura. The term "Nen" can also be used in conversation to refer to aura. A person capable of utilizing Nen, or in simple terms use and manipulate their life energy is colloquially referred to as a "Nen user" while those who cannot go by the designation "non-users". Now, nen users you've encountered so far are me, Hisoka, examiners from Hunter Exam and your family."

Killua nodded at the information.

"So, to continue, the reason why Nen is a secret unknown to large public is because everyone has life energy and thus can become nen users. Now, Nen is considered to be a dangerous power because there are a great varieties of monstrous feats one can create with Nen. To maintain the balance of power in this world, Nen is kept a secret and nen users avoid drawing too much attention to keep it that way. It is even considered Taboo to talk about it to non-users." Sachiko explained.

"Seems like a funny reason to me." Killua said.

"Yes, anyway, to be able to use Nen, you have to open your aura nodes. That's the first step you have to take to become a nen user. There're two methods to achieve this. First is manually open and close your aura nodes by meditating. It takes some time but it is a route you normally take."

"What about the second?"

"Well, second is forcefully opening your aura nodes by getting attacked or an experienced teacher opening them for you. That method is however, frowned upon because it's like cheating and the danger that comes with it." Sachiko explained.

"So, I have to use the first method if I want to open my aura nodes." Killua deduced.

"That'll be better. Besides, it shouldn't take you more than a week." Sachiko said. "Normally, even talented students would take at least months."

"Alright, I will use the first method."

"Good, now I'll explain you how to do it." Sachiko then started explaining on how to meditate and open the nodes.

In the anime, Wing said Killua and Gon would take less than a week if they opened the nodes by meditataion method so Sachiko couldn't help but wonder how long it would actually take Killua.

After explaining, she let Killua go back to his room to meditate. But, before he went back, Killua asked, "What about Gon? You kinda said you'd teach us both.."

"Don't worry. He'll get the same explanation and all when he recovers. In the mean time, you better work hard to achieve your goals as well. Time is essence, kiddo. You can have fun with Gon when he wakes up and even help him with his training from time to time." Sachiko told him.

Killua seemed to agree on that as he now had a burning desire to get stronger. "I will."

As Killua left, Sachiko smiled, watching his back. "Now that's me pushing Killua to pursue strength instead of just letting Gon decide his pace. Good work, me!"

------------------------------------

Sachiko chan's update stats

Name : Nakamura Sachiko

Alias : None.

Age : 19

Relationships : Gon Freecs (Close Friend), Killua Zoldyck (Adopted brother), Kurapika (Friend), Leorio Paradinight (Friend), Hisoka (Rivals), Illumi (Enemy), Geto Suguru (Enemy), Gojo Satoru (Acquaintance ), Wing (Acquaintance).

Assets : 225 million yen, 800 million jenny house, 100,050,000 jenny.

Hunter level : C

Jujutsu sorcerer level : Grade-1

Cursed technique : Cursed energy manipulation (Proficient), Time Manipulation Eyes (Advanced beginner), Nullify (Novice), Pain killer (Competent), Reverse Cursed Technique (Advanced Beginner).

Cursed energy : 9400/10,000

Cursed energy reserves rank : C

Nen Techniques: Ten (Proficient), Ren/Ken (Competent), Zetsu (Proficient), Gyo (Competent).

Nen Abilities: None.

Nen Type: Manipulator, Transmuter.

Aura pool: 78,000 units

Curse points : 280.

Hunter points : 20.

Cursed tools : Special Grade Scythe.

Skills : Intermediate Sword Skill (Competent), Assassins Art: Shroud (Competent), Assassins Art : Silent gaits, Rhythm Echo (Competent), Disguise (Novice).

Abilities : Enhanced sense : Eyesight , Super Hearing, Superior Strength (20x), Enhanced Reflexes.