Promise
𝐴𝑓𝑡𝑒𝑟 𝑎 𝑡𝑟𝑎𝑔𝑖𝑐 𝑎𝑐𝑐𝑖𝑑𝑒𝑛𝑡 𝑡𝑎𝑘𝑒𝑠 𝑌𝑢𝑗𝑖'𝑠 𝑝𝑎𝑟𝑒𝑛𝑡𝑠, 𝑆𝑢𝑘𝑢𝑛𝑎 𝑎𝑛𝑑 𝑌/𝑁 𝑑𝑖𝑠𝑐𝑜𝑣𝑒𝑟 𝑐𝑜𝑛𝑓𝑙𝑖𝑐𝑡𝑖𝑛𝑔 𝑤𝑖𝑙𝑙𝑠 𝑛𝑎𝑚𝑖𝑛𝑔 𝑡ℎ𝑒𝑚 𝑏𝑜𝑡ℎ 𝑎𝑠 𝑡ℎ𝑒 𝑡ℎ𝑟𝑒𝑒 𝑦𝑒𝑎𝑟 𝑜𝑙𝑑'𝑠 𝑔𝑢𝑎𝑟𝑑𝑖𝑎𝑛.𝐹𝑜𝑟𝑐𝑒𝑑 𝑡𝑜 𝑙𝑖𝑣𝑒 𝑢𝑛𝑑𝑒𝑟 𝑡ℎ𝑒 𝑠𝑎𝑚𝑒 𝑟𝑜𝑜𝑓 𝑎𝑛𝑑 𝑠ℎ𝑎𝑟𝑒 𝑐𝑢𝑠𝑡𝑜𝑑𝑦, 𝑡ℎ𝑒𝑦 𝑐𝑜𝑢𝑙𝑑𝑛'𝑡 𝑏𝑒 𝑚𝑜𝑟𝑒 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑡 𝑜𝑟 𝑚𝑜𝑟𝑒 𝑑𝑒𝑡𝑒𝑟𝑚𝑖𝑛𝑒𝑑 𝑡𝑜 𝑘𝑒𝑒𝑝 𝑌𝑢𝑗𝑖.
Sukuna x Fem!Reader | Strangers → Enemies → Lovers | Slow Burn
𝘾𝙒: 𝘿𝙚𝙖𝙩𝙝, 𝙜𝙧𝙞𝙚𝙛, 𝙤𝙧𝙥𝙝𝙖𝙣𝙝𝙤𝙤𝙙, 𝙘𝙝𝙞𝙡𝙙 𝙡𝙤𝙨𝙨 𝙤𝙛 𝙥𝙖𝙧𝙚𝙣𝙩𝙨, 𝙘𝙪𝙨𝙩𝙤𝙙𝙮 𝙘𝙤𝙣𝙛𝙡𝙞𝙘𝙩, 𝙩𝙧𝙖𝙪𝙢𝙖, 𝙝𝙤𝙨𝙥𝙞𝙩𝙖𝙡𝙞𝙯𝙖𝙩𝙞𝙤𝙣, 𝙛𝙪𝙣𝙚𝙧𝙖𝙡/𝙗𝙪𝙧𝙞𝙖𝙡, 𝙚𝙢𝙤𝙩𝙞𝙤𝙣𝙖𝙡 𝙙𝙞𝙨𝙩𝙧𝙚𝙨𝙨. 𝙁𝙤𝙧𝙘𝙚𝙙 𝙥𝙧𝙤𝙭𝙞𝙢𝙞𝙩𝙮 • 𝙁𝙤𝙪𝙣𝙙 𝙛𝙖𝙢𝙞𝙡𝙮 • 𝙎𝙡𝙤𝙬 𝙗𝙪𝙧𝙣 • 𝙈𝙪𝙩𝙪𝙖𝙡 𝙝𝙚𝙖𝙡𝙞𝙣𝙜 • 𝙀𝙣𝙚𝙢𝙞𝙚𝙨 𝙩𝙤 𝙡𝙤𝙫𝙚𝙧𝙨
Part 1
The ringing of Sukuna's phone cut through the sound of metal scraping against metal.
He frowned, wiping the grease from his hands onto an old rag as he stood from beneath the hood of the car he'd been working on all afternoon. His muscles ached, his shirt stained black with oil.
He almost ignored the call.
"...Yeah?"
"Mr. Ryomen?"
"...Speaking."
The voice on the other end was careful.
"Sir... this is the police. We need you to come to St. Mary's Hospital immediately."
His brows knitted together.
"...Why is that?"
pause.
"There has been an accident involving your younger brother."
Everything after that became a blur. The rag fell from his hand. His toolbox remained open. The garage door was left half raised. He didn't remember grabbing his keys. He didn't remember locking the house. He only remembered driving.
Red lights. Horns. People yelling as his car sped through traffic.
His hands squeezed the steering wheel so tightly his knuckles turned white.
No.
No, his brother couldn't be-
He gritted his teeth harder.
Don't think.
Just drive.
The hospital appeared before him like a nightmare.
He barely parked.
The receptionist had barely finished giving him the room number before he was already running.
His heavy footsteps echoed through the hallways.
Fourth floor.
Room 412.
He stopped.
His feet refused to move another inch.
The door stood a few steps away.
Outside it...
Someone was crying. Hard
The kind that came from somewhere deep inside a person's soul.
Broken
Hopeless
A young woman sat on a chair beside the office door, her face buried in her hands as sobs wracked her body.
He didn't recognize her .
He couldn't think.
Couldn't breathe.
Couldn't...
He slowly reached for the handle.
The room wasn't a hospital room.
It was an office.
Two empty chairs.
A desk.
Silence.
Sukuna remained standing.
His eyes never left the floor.
Minutes passed.
Or maybe seconds.
He couldn't tell anymore.
Then the door opened.
A doctor entered.
Behind him...
The same girl stumbled inside, wiping at tears that refused to stop.
She looked barely able to stand.
Before the doctor could even sit...
"Are they going to be alright?"
Her voice cracked.
Hope, desperatio, fear.
It all mixed together into one heartbreaking question.
The doctor froze.
He looked at his papers.
Not at her. Never at her.
Sukuna noticed.
He already knew.
Doctors only avoided eye contact when they had bad news.
His stomach twisted.
"...I'm deeply sorry."
The room became painfully quiet.
"The couple were involved in a severe traffic collision."
Another pause.
"We did everything we could."
"...But they didn't survive."
Silence.
Absolute silence.
Sukuna stared at the floor.
He didn't move.
Didn't blink.
It was almost as if a part of him had expected those exact words the moment the phone rang.
His chest felt...
Empty.
Not pain.
Not yet.
Just...
Nothing.
Beside him-
"What...?"
The girl whispered.
"No..."
She laughed.
A shaky, broken laugh.
"No, there has to be a mistake."
She stood so quickly the chair scraped loudly across the floor.
"Maybe you are talking about someone else?."
Her breathing became uneven.
"See..they don't even drive on that road."
She looked at the doctor desperately.
"You mixed them up."
"You have the wrong people."
She smiled through tears.
A smile filled with denial.
"...Can I talk to her?"
The doctor slowly shook his head.
"I'm sorry, Miss_"
His voice softened.
"She passed away."
The smile disappeared.
The strength left her legs.
She collapsed back into the chair.
Then she cried.
Not loudly.
Not dramatically.
Just...
Completely.
Like someone whose entire world had been ripped away in a single sentence.
Sukuna still hadn't moved.
His head remained lowered.
His brother.
The annoying idiot who always called him when he needed help fixing something.
The man who laughed too loudly.
Who insisted family dinners mattered and that sukuna had to be there.
Who believed Sukuna wasn't as cold as everyone thought.
Gone.
His sister-in-law.
The woman who somehow treated Sukuna like family from the first day she'd met him.
Who always packed him extra food when they visited. Who smiled even when Sukuna never smiled back.
Gone.
His jaw clenched.
His breathing became heavier.
Then-
It hit him.
His eyes snapped upward.
"...They had a little boy."
His voice was calm.
Too calm.
"Where is he?"
The girl's head shot up.
Her eyes widened in horror.
"Oh my God..."
"Yuji."
She stood again.
"Oh my God—"
She grabbed the edge of the desk.
"Please..."
Her voice broke.
"Please don't tell me he's..."
The doctor immediately answered.
"No."
Both adults looked at him.
"The boy is alive."
The girl collapsed into the chair again.
A sob escaped her lips.
She covered her face.
"Thank God..."
Sukuna swallowed.
"...Is he hurt?"
"No."
The doctor looked at the file.
"He was secured in the back seat."
"Physically, he has no injuries."
Sukuna finally allowed himself one slow breath.
The first one he'd taken since arriving.
"He appears to have lost consciousness during the collision."
The doctor continued quietly.
"We have him speaking with one of our child psychologists."
"We need to determine whether he witnessed anything traumatic."
Sukuna nodded once.
"...Good."
He stood.
"I'm going to get him."
He barely took a step before the doctor spoke again.
"I'm sorry, Mr. Ryomen."
Sukuna stopped.
"There are legal procedures."
His shoulders stiffened.
"Your brother and his wife left a will."
"We're contacting everyone named in it."
"There are custody protocols we must follow before releasing the child."
Sukuna stared at him.
Every second spent talking felt like another second Yuji was alone.
He wanted to go to him.
Now.
The doctor continued.
"Until everything is verified..."
"We cannot release him."
Sukuna closed his eyes.
He inhaled slowly.
Then nodded.
"...Fine."
His voice was hollow.
He didn't care what papers needed signing.
Didn't care who was listed.
Didn't care what the law said.
Even if Yuji ended up in temporary care...
Even if he was sent to an orphanage...
It wouldn't matter.
He'd find him.
He'd bring him home.
Because his little brother wasn't here anymore.
And Sukuna refused to let the last piece of him disappear too.
Outside the office, the hallway was unbearably quiet.
Inside, three people sat drowning in the same grief.
One had lost her best friend.
One had lost his little brother.
And somewhere else in the hospital...
A little boy still didn't know that the last time he had seen his parents...
...had truly been the last.
The room was painfully quiet.
Not the comforting kind.
The kind that pressed against your ears until it became unbearable.
A rectangular wooden table divided the room.
Three chairs.
Three people.
Sukuna sat on one side, elbows resting on his knees, hands clasped tightly together. His eyes never left the floor.
Across from him sat Y/N.
Her face was swollen from crying.
Her eyes were red.
Yet somehow...
She had stopped crying.
Not because she was okay.
Because she had cried until there was nothing left.
Between them sat the lawyer.
He adjusted the stack of documents in front of him before speaking.
"I'd first like to offer my condolences."
Neither of them answered.
The lawyer nodded once, understanding.
"I'll begin reading Mr. Jin's itadori final will, we wait for ms. Itadoris to arrive"
The sound of paper turning echoed through the room.
"Mr. Jin itadori leaves all financial assets, savings, investments, and property to his son, Yuji itadori."
Neither of them reacted.
"The inheritance will remain in trust until Yuji reaches the age of eighteen."
Another page.
"A separate amount has been designated to Mr. Itadoris brother..."
His eyes lifted briefly.
"...Mr. Sukuna Ryomen itadori."
Sukuna didn't move.
Money.
His brother could have left him every yen he owned.
It wouldn't bring him back.
It wouldn't bring Kaori back.
The lawyer continued.
"Now..."
He adjusted his glasses.
"Regarding the custody of Yuji itadori."
For the first time...
Sukuna looked up.
The lawyer read carefully.
"'Should anything happen to both myself and my wife, I appoint my brother, Sukuna Ryomen itadori, as legal guardian of my son until he reaches adulthood.'"
Silence.
Sukuna closed his eyes.
A tiny breath escaped him.
His brother...
Had trusted him.
Despite everything.
Despite the distance between them.
Despite Sukuna believing he wasn't made to raise children.
Jin had chosen him.
Because he knew...
No one would protect Yuji more fiercely.
Then-
A knock.
Everyone looked toward the door.
A man in a dark suit stepped inside.
"I'm sorry for interrupting."
He leaned toward the lawyer, whispering something too quietly to hear.
Then he slid another sealed document across the desk.
The lawyer frowned.
He examined the seal.
Opened it.
Read the first lines.
His expression changed.
"I see..."
The messenger quietly excused himself.
The room fell silent again.
The lawyer looked between Sukuna and Y/N.
"It appears..."
He hesitated.
"...Mrs. Kaori Ryomen also left an individual will... I'm just gonna go ahead and read it out loud for you ..."
Sukuna frowned.
"...Read it."
The lawyer nodded.
He unfolded the document.
"'I leave all personal assets, savings, and possessions to my son, Yuji itadori.'"
Nothing unusual.
Then-
"'Regarding Yuji's guardianship...'"
The lawyer's voice slowed.
"'Should anything happen to me and Jin...'"
Y/N's fingers slowly curled into her sleeves.
"'...I entrust the care, upbringing, and legal guardianship of my son to my closest friend'"
The lawyer looked up.
"...Miss_."
Everything stopped.
You froze.
Sukuna froze.
The room became impossibly still.
Sukuna slowly turned his head toward her for the first time.
She...
Was the person Kaori had chosen?
The lawyer placed both documents beside each other.
"The issue..."
He sighed quietly.
"...is that both wills appear to have been signed on the same date."
Sukuna frowned.
"What does that mean?"
"It means..."
The lawyer chose his words carefully.
"We cannot determine which document was written last."
"It is entirely possible Mrs. Itadoris later changed her mind..."
He tapped Kaori's will.
"...or that Mr. Itadori never knew she drafted this."
"There is no evidence provingeither scenario."
Sukuna stared at the papers.
His head already hurt.
"So which one counts?"
"Legally?"
The lawyer folded his hands.
"Neither has priority at this moment."
Another painful silence.
"Until the matter is resolved..."
He looked at both of them.
"...custody will be shared."
Sukuna's jaw tightened.
"Unless..."
The lawyer continued.
"...one guardian voluntarily relinquishes their rights."
"No."
The answer came immediately.
Firm, cold, Certain.
Sukuna hadn't even allowed the lawyer to finish speaking.
He didn't even glance toward Y/N.
There wasn't a universe where he would let Yuji go.
Not after today.
Not after losing Jin.
Not after promising himself-
He would protect the only family he had left.
He expected the woman beside him to agree.
To say she wasn't family.
To admit she'd only been Kaori's friend.
To leave Yuji with his uncle.
Instead...
Y/N spoke quietly.
"...I'd like to keep him."
Sukuna slowly turned.
His eyes met hers.
For the first time...
Anger cut through the grief.
Not loud.
Not explosive.
Just...
Hot.
Raw.
Painful.
She still wasn't looking at him.
Her hands rested tightly in her lap.
Her voice barely above a whisper.
"But..."
She swallowed.
"If Kaori trusted me with her son..."
Her lips trembled.
"...I can't ignore her last wish."
Sukuna stared.
Who was she?
What right did she have?
He had just buried his brother in his mind.
He hadn't even seen the body yet.
All he wanted...
Was to take Yuji home.
To make sure the little boy wasn't alone tonight.
And now...
A stranger was standing between him and that.
His voice came out low.
Controlled.
"What can I do..."
He looked only at the lawyer.
"...to receive full custody?"
The lawyer remained calm.
"I'm afraid nothing immediately."
"There will likely be an investigation."
"We'll need witnesses."
"Dates."
"Verification."
"Perhaps handwriting experts."
"It could take time."
"Months."
Maybe longer.
Sukuna's fingers dug into his palms.
"I don't have months."
The lawyer looked at Y/N.
"The only immediate alternative..."
"...is if Miss Y/N voluntarily surrenders her custodial rights."
Sukuna finally looked at her.
Really looked.
His eyes were bloodshot.
Exhausted.
Red from holding back tears he'd never allow to fall.
There was no hatred in them.
Only desperation.
A silent plea buried beneath pride.
Please.
He's all I have left.
Y/N felt his stare.
It made her chest tighten.
She finally forced herself to look at him.
He looked...
Broken.
Not angry.
Broken.
For a split second...
She almost said yes.
Almost.
Then Kaori's voice echoed inside her head.
"If anything ever happens to us..."
"Promise me you won't let Yuji feel alone."
"Promise me you'll protect my baby."
She had laughed back then.
Told Kaori to stop saying such ridiculous things.
Kaori had smiled anyway.
"Just promise me."
Y/N had promised.
A promise made over coffee.
A promise neither of them believed would ever matter.
Until today.
She slowly looked away from Sukuna.
Back toward the lawyer.
"...No."
The word was barely audible.
"I would like to keep him."
Her hands trembled under the table.
"If Kaori trusted me..."
She closed her eyes.
"...then I have to honor that."
Silence.
Sukuna leaned back.
His eyes closed.
He inhaled deeply through his nose.
Slowly.
Painfully.
He stayed like that for several seconds.
Because if he opened his mouth now...
He wasn't sure what would come out.
Anger.
Grief.
Or the desperate cry of an older brother who had just lost everything in a single afternoon.
The lawyer quietly gathered the papers.
Neither guardian noticed.
Neither cared.
Somewhere else in the hospital...
A three year old little boy sat coloring with a child psychologist.
Completely unaware...
That the two people now fighting to bring him home...
Were both trying to keep the same promise.
The last promise they had ever made...
To his parents.
The lawyer had barely finished organizing the documents when another gentle knock came from the door.
"Come in."
The child psychologist stepped inside.
Behind her stood a tiny boy with messy pink hair.
He clutched a drawing in one hand, a handful of crayons in the other.
His big brown eyes wandered around the unfamiliar room.
He looked confused.
Curious.
Still completely unaware that his entire world had ended only a few hours ago.
Then...
His eyes landed on Sukuna.
They lit up.
"UNCLE KUNAAA!"
His little legs immediately carried him across the room.
The drawing slipped from his hand as he ran.
No hesitation.
No fear.
Just relief.
A familiar face.
Finally.
Sukuna stood instinctively.
Before anyone realized it, Yuji had thrown himself against his legs.
Tiny arms wrapped around him as tightly as they could.
"Uncle Kuna!"
Sukuna bent down without thinking.
One arm slid beneath the little boy, lifting him effortlessly into his chest as though he weighed nothing.
Yuji immediately buried his face against his shoulder.
Safe.
He was safe now.
Sukuna wrapped both arms around him.
An actual hug.