Untrustworthy [Yandere JJK x Kakashi!Reader]

Chapter 7

(Y/n) was training in the training fields, alone, practicing her Jujutsu and precision of attacks. "Little sister~ You left Yuji alone?" Satoru called as he walked up to her, slinging an arm over her shoulders. "Of course, I don't need to watch over him" (Y/n) answered blandly, as she stopped her training.

"Ah, I guess you're right, well, I have a little job for you! Come along" Satoru chirped as he brought her close to his chest. Before she could protest, she is already inside the basement Yuji is hunkered down in. "Yuji~!" Satoru cooed, earning a small shriek from the boy. "Gojo-Sensei? (Y/n)? What's up?" Yuji asked as he turned his attention to the two.

"He's got a mission for us" (Y/n) grumbled as she pointed her thumb at Satoru. "Yup! Now, off we go" Satoru said with a large smile as he grabbed Yuji. Before they could blink they found themselves on top of a lake, with a cursed spirit looking at them. "Sorry for the wait, hope I didn't keep you" Satoru cooed mockingly at the curse.

"Look (Y/n)! It's Mt. Fuji! His head looks like Mt. Fuji!!" Yuji exclaimed as he pointed at the curse. "Satoru, why are we in front of a beat-up curse? Are you trying to show off?" (Y/n) asked as she deadpanned at him. "Nope! Let me introduce you, this is Yuji Itadori, he'll be watching today. And here's my cute little sister! She will be the one to fight you in my place!" Satoru casually said as he pushed (Y/n) forward.

"What?!" (Y/n) and Yuji exclaimed, both not liking the idea. "Wait, isn't that dangerous?! Why is she fighting that thing?" Yuji asked worriedly. "Ha, pitiful, you're using a shield in your place?" Jogo mocked, despite having been beaten by the man earlier. "No, no, she's no shield, she can easily beat you. You see... You're just weak" Satoru said with a mocking smirk.

In an instant, the curse exploded, literally, startling Yuji from how pissed the curse is. "(Y/n) can't fight that thing! That thing isn't weak at all!!" Yuji exclaimed as he gripped Satoru's arm. "Great, you had to piss it off" (Y/n) grumbled unhappily, pouting behind her mask. She's slightly glad she has her eye covered, or else she'd be extra blinded by the amount of cursed energy sent at her.

Satoru placed a hand on top of Yuji's head, forcing his attention onto him. "Don't worry, I won't let anything happen to her if it gets out of hand" Satoru promised with a reassuring look. "Domain Expansion... Coffin of the Iron Mountain" Jogo said with a smirk as the trio was now trapped in his lava domain.

"Oh, I see, you want me to fight while you teach, classic" (Y/n) commented casually as she glanced around the area. "That, and I want to see how my little sister improved," Satoru said while clapping his hands together. "By setting her against that?!" Yuji exclaimed, finding it a bit excessive. "Well, Special Grade? Are you going to fight me?" (Y/n) taunted earning a wide-eyed expression from Yuji.

"Cocky runt, you'll melt before I even touch you. Why don't you run home?" Jogo mocked as he waved his hand at her. Sparks clicked around her, almost unnoticeable as the sparks from the lava looked similar. Jogo smirked as a wall of rock headed straight for her. "(Y/n)! Look out!!" Yuji yelled as he goes running to her, only for Satoru's hand to snag his hood and pulled him backward.

Lightning erupted around (Y/n) as it shoot through the rocks, forcing it to explode before it touched her. "Woah..." Yuji muttered in awe, as he spotted lighting in her hand. "See? Isn't my little sister the best? She's getting so much better" Satoru cooed as he fangirled over his "sister". "She is... Amazing" Yuji muttered, why did he ever cheat on someone like her?

Unknown to him, Sukuna was also watching, pleased by how well-trained his future wife is. A strong wife also means strong kids. "Is that all you got, Mt. Fuji?" (Y/n) taunted as she dusted off the imaginary dirt off her clothes. "Don't mock me, you insolent brat! I will turn your bones to ash!" Jogo yelled as he sent a wave of lava at her.

"Huh... That rhymed" (Y/n) noted casually as she glanced behind her, and right at Satoru. Her "brother" smirked as let down his blindfold. "I guess I can step in now," Satoru said with a shrug, as the wall of lava seemingly stopped before it hit (Y/n). "Domain Expansion... Infinite Void" Satoru said as they got engulfed in darkness. But, before (Y/n) and Yuji could be affected by it, Satoru picked them both up.

"You did a good job sparing with my sister, you really held out," Satoru said as he placed a hand on top of Jogo's head. (Y/n) hung onto her "brother's" back, looking a bit bored. "Honestly, why did you bring me here? This was pointless" (Y/n) grumbled. She had a point, why was she here if Satoru was going to just kill the curse anyways? His logic never made sense.

"Well... I also wanted to show off to you, little sister" Satoru chuckled as he easily ripped off the curse's head. Instantly, the domain was released as he plopped the two on solid ground. The two students watch as their teacher tormented the poor curse. "Hey, (Y/n)- I-I mean Hatake! How come you couldn't lay out your domain?" Yuji asked nervously.

"Simple, I don't know how to make a domain yet" (Y/n) answered as she looked at him. Domain Expansion is a hard task to accomplish. So far, she only knows 3 beings who are able to accomplish it, Satoru, Yuta, and this cursed spirit under Satoru's foot. "Hey, I just realized, is it normal for cursed spirits to talk?" Yuji asked with a look of confusion.

"How did you just realize that?" (Y/n) questioned in disbelief, how did she date someone this stupid? Her thoughts were interrupted by a projectile almost hitting Satoru. Unexpectedly, flowers surrounded them, forcing them to drop their guard completely. "Awe/So pretty" Satoru and Yuji cooed, while (Y/n) silently eyed the flowers, wanting to desperately pick one.

Satoru quickly snapped out of it, realizing it was a curse technique, this wasn't the same for Yuji. "Wah!!" (Y/n) shrieked, instantly snapping Yuji out of it. "(Y/n)!!" Yuji called as he tried grabbing her, only to miss her by a hair. Satoru worriedly looked at his precious "sister" being lifted into the air. The cursed used the destruction to rescue Jogo and scurried away.

"Shit! Stupid fucking curse!" (Y/n) exclaimed as she hastily pulled out a cursed weapon and cut her way free. "I got you!!" Yuji called as he attempted to try and catch her. Satoru quickly took out the cursed plant before it could do more harm as (Y/n) landed directly into Yuji's arms. "Gah... Remind me to never go on missions with you again, Satoru" (Y/n) grumbled as she lay limply in her ex's arms.

"Oh, don't be like that, little sister! You know you love going on missions with me" Satoru chirped happily. Yuji sparkled as he gets to happily hold his ex again, god how he had missed her touch. He's never washing this hoodie again, as he hopes her smell rubs off on it. Maybe if he holds her longer her smell will seep into his pores!

"Alright, Yuji, I want you and (Y/n) to train together for the next month. But you'll also have to watch movies, Yuji" Satoru said as he pointed at the two. "What?!" (Y/n) exclaimed as she jolted up, not at all happy with this plan. "Really?! I get to train with her?" Yuji asked with a large smile, this is a dream come true! Well, not fighting her, but getting to spend time with her for a month!

"And, you'll both go on missions, but she's going to watch over you not help you. You will learn the basics and how to apply them. Then you can show off all these new skills at the exchange event! (Y/n) will even be an audience this time!" Satoru explained with a happy smile. "Wait, I won't be participating?" (Y/n) asked, having not heard of this new plan.

"Teacher!" Yuji called out with a serious look, but whined when (Y/n) got out of his hold. "Yes, Yuji?" Satoru asked as he pointed at his student. "The exchange event is... What?" Yuji asked with dotted eyes, earning silent stares from Satoru and (Y/n). "Ah? I didn't tell you?" Satoru asked, causing (Y/n) to smack her own face lightly, she underestimated how bad his teaching skills are.