In the shadows of Konoha,

a secret was born that even the Uchiha themselves never knew.

Mikoto Uchiha carried not one child

... but two.

Yet, not even Fugaku, not even her eldest son Itachi, knew the truth.

On the night of their birth,

fate was twisted.

**A nurse,**

once in love with Fugaku, fire🔥

allowed jealousy to guide her.🔥 When the twins came into this world,

she stole the girl-the second child-and vanished into the night.

She named the child Sin. Not out of love, but as a mark of the crime she carried in her heart. A sin against her clan. A sin against fate itself.

And so, the world believed the Uchiha had only two children: Itachi, the prodigy, and Sasuke, the younger heir. But in the shadows, another bloodline lived.

This is the story of the forgotten twin... the one they called Sin, the hidden Sharingan of the Uchiha.

Sin: 13 years old

Renji: 13 years old

Setting: Sin is disguised as a boy to hide her true identity. She attends a shinobi training school reserved only for boys, where she blends in with the other students. One night in the dormitory, while the other boys rest, she talks with her spoiled classmate Renji—the grandson of the Tsuchikage.

                       the Sin of the Clan

Sin lay on her back, staring at the ceiling, her voice low but steady as she spoke to her friend beside her.

"Her name was Reina Nara… a nurse in Konoha’s hospital. Everyone only saw her as gentle, quiet, and kind. But she carried a secret that changed my entire life."

Her lips curved into a faint, almost sad smile.

"The night I was born, my mother  gave life to twins. Sasuke… and me. But Reina made a choice. She took me from the clan that night and disappeared. It was a crime—stealing me away from my roots"

She turned her head, eyes soft, not angry.

"But to me… she was never my kidnapper. She raised me as her own child. She fed me, held me when I cried, taught me to walk, to speak… to live. She gave me the only life I’ve ever known. She was my mother. In every way that mattered."

Her voice grew quiet, almost a whisper.

"She named me Sin… to remind herself of the mistake she made that night. But to me, that name is not a curse. It’s just… who I am."

Sin’s voice was calm as she spoke of her childhood—the quiet nights, the woman who raised her, the life she’d known in the shadows. She didn’t say much, but enough for Renji to hear.

Renji scoffed and flopped onto his back, arms behind his head. “That’s it? Hah. Sounds boring. If I grew up like that, I’d have gone crazy. Glad I was born a Tsuchikage’s grandson.” He grinned, puffing his chest like he had just won something.

Sin sighed, turning her eyes away. His arrogance didn’t bother her—she never cared for his bragging. But then, almost casually, almost teasing, she added:

“What if I told you… I’m actually a Uchiha?”

Renji turned his head, blinking once before bursting out laughing. “A Uchiha? You? Come on, don’t joke. You can’t just throw around famous clan names like that to sound cool.”

She smirked faintly, pretending it was all a game. “Maybe I’m serious.”

Renji snorted. “Yeah, right. If you were, you’d have that… what’s it called… Sharingan? Those red eye things. I don’t see any.”

He shook his head, but then paused, frowning in thought. “Wait… Uchiha… Uchiha… why does that sound so familiar?” He scratched his chin, muttering. “Grandpa said something once. Konoha… there was a clan… ah!”

His eyes lit up. “That’s it! The Uchiha. They’re gone. Completely erased. Wiped out years ago. My grandpa told me the whole thing. Big deal at the time. You’re way too late to be one of them.”

Renji smirked like he had solved a puzzle, then rolled back onto his side. “So yeah, nice try. You almost got me.”

“…All gone?” she asked carefully, her tone playful but her eyes sharper. “You mean… no survivors?”

Renji shrugged. “That’s what Grandpa said. Some Uchiha killed his own clan—imagine that! The Sharingan turning on its own. Hah. Guess even their eyes couldn’t save them.”

He laughed at his own words, completely unaware of the weight they carried.

But Sin lay frozen. The air around her felt heavy, the words echoing in her mind. Erased? Gone?

She had only been fishing for answers, but what she caught instead was a truth sharp enough to cut through her chest.

Monologue

I remember the night I was taken. I was just a baby, too small to even know who I belonged to. All I ever knew… was her. The nurse. The woman who raised me.

She never lied to me. She never claimed to be my real mother, but she never told me about my roots either. And I never asked. Maybe I was afraid of the answer. Or maybe I just didn’t care. She was enough. She was my mother in every way that mattered.

But people around her… they didn’t see it that way.

They whispered. They stared. She was unmarried, and suddenly she had a child. They knew her family, they knew she had no husband. So… whose baby was I? They didn’t believe her silence. They didn’t forgive it either.

That’s when he appeared. A man with power, with money, with a cruel heart. He had always wanted her. And then he heard me cry, hidden in her home.

He told her that if she wanted to keep me safe, to keep me secret… she would belong to him.

It wasn’t love. It wasn’t kindness. It was a bargain.

She agreed. For me. For the child she shouldn’t have had.

I grew up never questioning it. I didn’t search for where I came from. I didn’t search for anyone else. I had her. She chose me, even if I wasn’t her blood. She chose to fight for me. To me, she was my mother. Always.

I remember that house. Cold walls, colder than the winter nights in the Stone village. Reina… she tried her best, she really did, but the man she chose.... he was nothing but poison.

He never once looked at me with warmth. To him, I was a mistake that never should’ve breathed. He treated Reina no better. He spoke to her like she was dirt, like she was some prize he had won but quickly grew bored of. And me? I was worse. His anger always seemed to land on me..... every shout, every glare, every drunken stumble through the door.

I hated the smell of him when he came home late, reeking of alcohol, complaining that Reina wasn’t enough. Comparing her to other women. Saying she was weak, useless. I remember clenching my little fists, wanting to shout back, but Reina would just shake her head.

She never lied to me, never called herself my mother... but she held me close when he spat his venom.

He hated me most of all. He saw me as a shadow of something he couldn’t stand, something he could never control. And maybe he was right. Maybe I was already too different.

Six years ago:

Name: Daichi Moriyama (大地, “Great Earth” – symbolizing strength, dominance, and foundation)

Age: 42

Occupation: Wealthy businessman / influential figure in the village

Personality: Cruel, arrogant, controlling, manipulative, and a notorious womanizer

Background: A corrupted man who holds significant power in the village, feared and resented for his bad reputation. Comes from a wealthy family and uses his influence and money to get what he wants

The night had settled like a heavy blanket over the city. Rain tapped relentlessly against the window, each drop echoing the tension inside the house. Shadows flickered across the walls, distorted by the dim light of a single swinging bulb. I huddled in the corner of the living room, clutching my knees, while Reina stood close, her small frame tense, ready to protect me.

The smell of sake filled the room as Daichi staggered in, his robe half-open, eyes glazed but sharp with cruelty.

Daichi (slamming the door shut behind him):

"Tch… there you are. Always waiting like some obedient wife. Pathetic. You think this is enough for me, Reina? You? Hah. Look at yourself. Worn out. Dull. Not even worth a glance anymore."

Reina flinched, clutching Sin closer. Sin’s little hand tightened in her sleeve, eyes wide, her breath shallow.

Reina (steady, but low, pleading):

"Daichi… please. She’s here. Don’t say such things in front of her."

Daichi (sneering, his voice rising):

"What? She needs to hear it! That brat isn’t mine, and you..... you’re nothing but a burden I dragged into this house. Do you think I won’t throw you both out? Hah! Maybe I should. Maybe I should bring real women here...... women worth a damn..... fill this place with them and let you rot in the corner."

He staggered closer, leaning over Reina, the stench of alcohol heavy on his breath.

Daichi (mocking whisper):

"You’d watch me, wouldn’t you? You’d stay because you’ve got nowhere else to go. You’d cling to me, even if I spit on you."

Reina’s lips trembled, but she straightened her back, forcing herself between him and Sin.

Reina (voice breaking but firm):

"You will not touch her. Not with your words, not with your hate. Whatever you do to me, Daichi… you leave her out of it."

For a moment, his expression twisted.... disgust, and rage tangled together. Then he burst out laughing, a cruel, hollow sound.

Daichi:

"Leave her out of it? You really think anyone would take her in if I threw you out? She’s nothing, Reina. A nameless brat. Without me, you’re both dead."

He shoved past them, collapsing onto the mat, grabbing another drink from the floor.

Sin buried her face into Reina’s side, her small voice trembling.

Sin (whispering):

"Reina…?"

Reina pressed a hand to her daughter’s head, holding her tighter, even as her own body shook.

Reina (soft, almost to herself):

"He doesn’t matter. You matter. Don’t ever believe his words, Sin… you’re all I have. And I will protect you… always."

But her eyes, staring into the shadows where Daichi lay drinking, were filled with dread.

                         ..................................

Sin pov

" I stopped being a child. I stopped laughing. I stopped dreaming.

Daichi killed it all. Every time his drunken voice echoed in that house, it was like poison crawling up my throat. He didn’t just hate me.... he wanted me erased.

Do you know what it feels like to be seven years old and already praying for someone to die?

I’d clench my fists until my nails tore skin, just to keep from screaming.

My blood would drip, and I’d stare at it and think: better mine than Reina’s. Because he hurt her too. He broke her down piece by piece. And I hated him more for that than anything he ever did to me.

But I couldn’t save her. I was too small. Too weak. So all I did was burn inside.

Every laugh he had at her expense, every threat, every time he looked at her like she was trash..... those moments became knives. They stuck in me, over and over, until there was no room left for anything but rage.

I was just a little girl… but I wanted blood. His blood. I wanted to watch him choke on the same fear he fed us. I wanted him to know what it’s like to be powerless, to beg, to break.

I didn’t cry myself to sleep. I promised that one day, I’d be strong enough to end him. And that promise… it’s the only reason I survived."