Gojo entrusts them to join grade 1 sorcerer Kento Nanami on tough missions, as a means of advancing his pupil's abilities. Their very first assignment is to investigate the mysterious deaths by disfiguration that occurred in the City.
Corpses of three high school boys were found in the theatre by the staff. According to the autopsy report, all three of them died from increased pressure to the brain and asphyxia due to severe cranial deformation.
Police offers who arrive on the scene allow the Jujutsu Sorcerers to take over the investigation. Nanami teaches Y/N and Yuji to see the residuals left behind by the cursed techniques, in which they succeed.
They follow the tracks until they reach the roof of the building, where they are confronted by two creatures that appear to be cursed spirits.
Yuji and Y/N prepares to attack but Nanami stops them and instructs the youngsters to take care of the other curse behind them.
He then approaches an eye bulging, twisted, long limbed, dull-hued, and elongated face, cursed spirit.
Nanami discloses the rules of his cursed technique and teaches them that doing so makes it more powerful. In one swift motion, Nanami chops off all the curse's legs and defeats it. Yuji and Y/N are amazed, Nanami can slash through curses even though his blade is wrapped up.
The second curse who had a white body and a vertical mouth with tiny eyes above it, takes Yuji by surprise because he was paying attention to Nanami.
Thanks to Gojo's training, Y/N now has a better control over her cursed energy. And Yuji on the other hand, discovered his cursed energy has a time lag. This allows his strikes to have the impact of two hits.
Y/N swiftly moves and uses her cursed energy and forces it towards the spirit. The force is so intense that it reverberates through the air, causing the spirit to fall back into the ground. Yuji then quickly begins to channel his cursed energy into his fists.
"Laundry detergent." the spirit kept on repeating the same words.
Before Y/N could do anything, Yuji reveals the name of his attack is "Divergent Fist", and uses it to instantly defeat the enemy before him.
"Thanks for saving me Y/N!" Yuji expressed.
Nanami takes notice of Y/N's immense impact and Yuji's massive potential before realizing the curse he defeated was wearing a watch. Shocked, Nanami takes out his phone and takes a picture.
As curses can't be perceived by normal means, they shouldn't appear in a photo taken by a phone camera. However, it does, meaning these creatures are actually in fact human.
Their remains are taken to Doctor Shoko Ieiri. While Y/N, Yuji and Nanami were resting on the couch, the sun shining through the window. She confirms the creatures are humans disfigured by Jujutsu.
This causes Yuji to develop a distasteful feeling. Y/N notices the change in his looks, the unpleasant look made her feel miserable. She didn't like to see him in such state.
As for Y/N, it didn't bother her. It was evident that they weren't responsible for their deaths, so she saw no need to dwell further on the matter.
"No matter what, their deaths bear the same weight on me. Even so, this is too distasteful." as Yuji said this, a vein popped up on his forehead.
In order to reassure Yuji, Nanami tells him that Shoko discovered their cause of death was due to cellular transmogrification and not their actions. Y/N places her arm on Yuji's shoulder and she starts to caress it while a reassuring smile covered her face.
Fired up, the three sorcerers agree to continue investigating the residuals until they find the culprit.
Sometime later, the investigation continues above ground with Y/N, Yuji, Nanami, and Ijichi overlooking the clues left behind by the murders, they were in a classroom.
Nanami tells them to meet with and possibly interrogate Junpei Yoshino, the only known witness. He also explains what's a Curse User.
Curse Users, the sorcerers who use jujutsu for evil and malicious deeds such as killing.
"Roger!" the three of them exclaimed, saluting Nanami.
"Speaking of which..." Yuji spoke.
"What?" Ijichi and Y/N exclaimed, glancing at Yuji.
"We don't know any other assistants aside from you, Mr. Ijichi." Yuji said turning towards Ijichi.
"Well, I am sure that it's cause he's the only one that knows we're still alive." Y/N explained poking Yuji's cheek playfully.
"It can't be helped." Ijichi said in a soft tone.
"I see." Yuji spoke as the three of them walked out of the room.
"Let's goooo!" Yuji enthusiastically said and Y/N nodded her head.
As they were walking, Ijichi turned around and walked back into the room where Nanami was, the two pups weren't aware of this and kept going forward.
After a few steps, they suddenly realised that Ijichi wasn't there with them. They took a U-turn and walked towards into the room.
"Nanami Sensei!" Yuji pushed Ijichi playfully out the doorway and then he peeked his head through the door. Below him, Y/N scooted doing the same.
"We forgot to tell you..."
"Take care!" Both Y/N and Yuji said, putting one of their hands up in the air.
Nanami stared at them, leaning on the board with his arms crossed.
"Itadori."
"I am not a teacher, so don't address me like that." Nanami cleared.
"Just Nanami then!" Yuji explained enthusiastically.
"I'll beat you up." Nanami warned and Y/N let out a chuckle while Ijichi sweat dropped.
Later, Y/N Yuji and Ijichi track down Junpei skipping school. He's caught by someone, and Ijichi plans to use a fly-head curse to test Junpei's awareness. The person talking to the witness complicates the situation. Y/N and Yuji awkwardly interrupts them to stop the fly-head.
In order to get in a conversation with Junpei, Yuji gets rid of that someone, who turns out to be Junpei's teacher, claiming that he felt Junpei disliked him anyway.
Yuji and Y/N manage to talk with Junpei at his school, situated by a lake, due to the evening hour and the golden sunrays, the lake sparkled. Despite their clashing personalities, they manage to bond over movies.
"What? Is that you, Junpei?" abruptly, a female voice questioned.
"Mother!" Junpei exclaimed.
"It's hard to find you here, are they your friends?" his mother asked with a smile on her face.
"I just met them." Junpei cleared.
"We just met but we can be friends!" Yuji declared.
"Yep! We sure can be!" Y/N expressed.
"Really? Please play with him more." she spoke as she put her hand up, which held a cigarette between her index and the middle finger.
"Mother..! Cigarettes." Junpei exclaimed and looked down at the ground.
Y/N and Yuji looked at him with a concerned yet interested expression.
"Didn't I tell you not to smoke...?"
"I'm sorry, I'm sorry. We agreed not to smoke in front of you." his mother said placing the cigarette in it's box.
She then walked over to Junpei asking for his friends name.
"I'm Yuji Itadori!" while putting his hand up, Yuji introduced himself a happy smile covering his face.
"And I am Y/N L/N!" Y/N introduced herself, waving at Junpei's mother as a sweet smile adorned her face.
She then offer the two to come over for dinner. Abruptly, Yuji's stomach growls, making the people around him look at him as his face showed embarrassment.
They accept the offer and eat at the Yoshino house, managing to get along very well with Junpei and his mom. Yuji then got a call from Ijichi, where he told him to come pick them up after two hours.
"You both are Jujutsu Sorcerers, right?" suddenly Junpei questioned.
"Yes." they both responded and exchanged looks for a moment.
"Have you guys ever killed anyone?" Junpei interrogated.
"No." they replied.
"But you'll need to fight other bad Jujutsu Sorcerers. What will you do then?" he continued to question.
"Even so, I don't want to kill anyone." Yuji cleared.
"Well, if they deserve death, I wouldn't think twice. But, deep down I would still not want to hurt anyone...willingly." Y/N cleared.
"Why not? they are bad people." Junpei asked.
"How should I put it... If i kill once, the option of killing would come in my life. The value of life becomes ambiguous. I won't understand the value of someone important to me. I'm scared of that." Y/N and Junpei looked at Yuji with a soft look on their face.
"I get what you're saying Yuji.. but personally.."
Yuji and Junpei's eyes shifted to Y/N.
"I..I don't exactly know what I really feel, but I strongly believe that individuals who take the lives of others, particularly those who don't deserve such fate is probably one of the thing I am against.
The person who died has people or a person in their life who..who would be shattered by hearing the news of their death, deeply impacting their lives, only cause of the criminal's tainted heart...I just can't stand it." Y/N expressed her feelings through her words.
Her mind recalled the two individuals who held immense significance in her life..the two she lost, worst part was that the reason for their death was still unknown, and she indeed gave up upon finding it, she knew that if she continued to held onto it, she would never get ahead in her life.
This conversation did make the three have their distinct thoughts lingering in their minds.
After they leave the house, Ijichi drops them at Nanami's place. Since they have been investigating, they decide to stay at Nanami's instead of Gojo's place. Which wasn't as awkward as they expected.
Nanami directed the two kids to head straight to bed without any interruptions. Y/N pouted at Nanami telling him that she wasn't a kid. In response, Nanami insisted that to him, she still qualified as a kid, regardless of her age. This only deepened her pout and Yuji look look at her giggling at her cute little pouty face.
The next day, the tragic news of Junpei's mother's death hit their ears.