Two against the world.

Twenty-Three Percent

| been in pain like me |

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Light's tenth birthday party is, well, quaint.

Most of the children from his class are scattered across the living room, some with cake on their face, some playing games meant for children their age.

Sayu sits perched at the top of the couch, watching the scene play out.

No, maybe not the scene.

Her eyes are frozen on her brother, who offers kind smiles and has that healthy blush on his face from all the attention. On the surface, he really does seem happy, glad when people shove wrapped boxes in his hand or bags overflowing with silk paper.

But if you dig, and Sayu does; because he reminds her so much of the previous her, the one who looked at the world with boredom laced with pain, the carefully constructed mask that tears at the edges, the smiles that become stiff and sharp eyes dart around for a clock, mind silently calculating the minutes left before it's all over.

Sayu's never had a big brother, well not the previous her anyways.

And while Light is older than her by two years, she still feels as if she has to look out for him, to ease his pain, to soothe his ache. She understands what it's like to be alone in a world that always wants something from you, that the expectations placed on your shoulders can weight you down (make you crazy).

She remains quiet through the whole celebration, watches carefully as people ask for Light's attention and for his participation. It's only when her mother is putting away the cake and all the children have gone home that she turns around and places her arms around him.

"Onii-chan." She whispers in his ear. He doesn't turn rigid at the touch, but he doesn't quite reciprocate it. "You don't have to play pretend with me. You can show me your true face and I'll still love you. I'll always be there."

One would look at the scene and think about how sweet the display is.

Sayu, the little sister, embracing her big brother, Light, on his birthday. She doesn't actually know how long her arms remain around him, but when she pulls away, his face has gone blank and his body doesn't move.

Light avoids her for three days after that. And then, on the fourth day, he pushes the door of her bedroom completely unannounced and sends her a look which she answers back.

It's far too serious for children.

But the moment passes and Light moves, let's himself fall on her bed, opening the book he is carrying. Sayu doesn't move from her desk chair and continues with the mindless coloring.

They understand each other and from that moment on (it's the two of them against the world).

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She is nine.

Whatever existential crisis she seemed to have when she turned seven is replaced by the knowledge that she is not quite her old self anymore, just like she'll never truly be Sayu Yagami - both personalities blur together to create a new tangible one.

Her class has to make a presentation on what they would like to be when they grow up (she remembers anatomy pictures and chemistry and physics).

Old her had been studying to be a doctor, had been overstressed and overworked, had been unable to please her demanding mother even if she tried so hard all the time.

But in this world, Sayu is her mother's little girl and she has a big brother to shoulder on the family's expectations. No one expects her to become some fancy doctor. Whatever she chooses, people won't comment on it.

Her teacher sends them to the school library to pick out a future presentation. Her hand hovers over the medical books for a moment because it's what she knows.

And then she makes a sharp left turn and instead grabs the book about Japanese Law.

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"Sensei asked us to make a presentation on what we would like to be when we grow up." It's the traditional Yagami supper. Her father is there and her mother has just asked her what she did in school today.

"That's nice, Sayu. What did you choose?" Even Light looks quite intrigued. It has to be said that Sayu doesn't share much with the family, always think carefully before opening her mouth.

She slips less often now, but she still does sometimes.

"I want to be a lawyer." Three pairs of eyes blink exactly at the same time. She smiles innocently, it's easy when you are in the body of a nine-year-old. "So I can put away the bad people that Otou-san and Onii-chan catch."

Her father loves her; she knows that much. This one at least. The previous one had been an absent father who sent late birthday cards and didn't care. But Sayu is her mother's little girl and Light is her father's little soldier.

And, at that moment, Soichiro's eyes shine with pride and he can't really hold back the smile that makes his stern face look somewhat younger.

Her father's pride and her mother's enthusiasm is just an added bonus to the fact that now her future is sealed with Light's forever. And from the look he sends her, he doesn't seem to mind.

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Light is sprawled on her bed, like he always does these days. Her brother can be reckless, but never in public. He's just entered Middle School, a private one, and spends much of his free time in her room.

She doesn't mind.

"You know, no one actually expects a ten-year-old to know the Modern Japanese Legal System's Six Codes by heart, Imouto." Fifth grade is boring; she might as well prepare herself for what lies ahead.

She looks up from the heavy book, a gift from her father who seemed very happy to spend the money so she could have her own copy (law books are pricey, but Soichiro is proud).

"And no one expects a twelve-year-old to be able to solve collegiate calculus problems, Onii-chan." Light is smart, too smart for his own good. Everything he does, he does it well and with an inhuman amount of ease.

"You have a point." He's smug and has an ego problem. While Light displays his knowledge for the whole world, Sayu is very happy to sit back and only answer questions when asked.

They make quite the pair.

Her mother shouts that it's time for her swimming lessons and Light's tennis practice.

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By the time she turns thirteen, Sayu understands that she can't bring friends over to her house, at least when Light is there. Her Middle School friends gush and blush when he is around and while he never shows an interest, it doesn't deter them.

Like Light needs another boost to his already massive ago.

But her brother, even with all his potential to become a womanizer, never has much of an interest in women. Sure, he'll use them if it's convenient – she doesn't blame him. He's a fifteen-year-old boy after all and people push their lives into his hands without ever thinking that he'll do them harm.

People are stupid like that.

Sayu's learned the Modern Japanese Legal System's Six Codes. She doesn't have to watch for slips anymore because she's thirteen now and thirteen years' old who know every Law in their country are allowed a bit of cynicism.

"You know, little sisters are supposed to ask their big brothers for help with their homework. Not make them go to the library to pick up books about International Law." She shrugs her shoulders.

"Like you had something better to do with your time." Her relationship with Light doesn't change even as they grow older. To the rest of the world, Light is the big brother who dotes on his little sister.

They are not wrong, but they are not right. People just don't bother to scratch the surface, to notice that Light isn't quite the kind upperclassmen and the wide-eyed prodigy they make him out to be. He manipulates everyone and everything so that they don't even realize it.

His mask slips when he's with her. And, just like she's promised all those years ago, she remains by his side.


a/n: The world (and L) should watch out for Sayu. I don't think they quite know what she has in store for them. To answer a few questions; yes, she is in another universe. Her old family doesn't exist anymore. No, she has never read Death Note before, but she won't have to be a part of this - especially given her relationship with Light.

Everyone's feedback is much appreciated. I love reading your reviews and I'm happy people enjoy this story. Thank you for reading and I hope you enjoyed. Till next time!