A/N: I can't believe I even have to say this but this is NOT an INCEST fic. I would never. (EW!)

I didn't want to call it out because I didn't want to spoil anything of this story but the relationship of Luffy & Emmy is this:

Luffy and Emmy are NOT BLOOD RELATED. I repeat, NOT ACTUALLY SIBLINGS. And here's the key point: THEY KNOW THAT!
They just call it brother and sister because that's the label that Garp gave them at the very beginning and they just went with it. Their bond does start off as a sibling/best friend relationship but has/will grow into romantic love. They are just not aware of that when it does happen because they are so close that they just assume this is a relationship between a brother/sister.

Okay, now stop commenting/msging me saying this is gross/taboo/incest fics are not your thing BECAUSE IT'S NOT MINE EITHER.

Ch 1 - I am the Moon.

-2 years before Luffy sets sail, Luffy: 15 years old-

Cold.

That was all the girl felt as she laid curled up in the middle of her cell. Her head rested on its side with her cheek pressed against the slightly damp wooden planks. Her thick blonde hair spilled all around her body and over her face. Her arms were clutched tightly around her chest with her knees tucked over them but yet she was still cold. The thin dress that she wore, although going all the way down to her ankles, offered no warmth. In actuality, she'd prefer to feel that way since the colder she was, the more numb she'd feel.

She wished for all her heart that the night air would turn even chillier just so that she wouldn't have to feel anything at all. She was actually thankful for the cold shackles that circled around her wrists. The Sea Prism Stone provided two benefits for the girl. It kept her power at bay and also made her feel completely exhausted. Feeling tired meant she didn't have to feel anything else and she was so tired of feeling.

Outside of her cell was the captain's bedroom. He had a large wooden bed with an ornate headboard, an oak writing desk, a matching chair, and, more importantly, a window. It was a small porthole but to the little girl, it was the size of her world. From it, while lying down at this angle, she could see the night sky.

Her cloudy blue eyes peaked through the openings of her blonde hair and she stared out the window in a daze. Tonight was a full moon and it shined directly back at her, like a parent reaching out to a child. I am the moon, the little girl chanted through her unblinking eyes. It had become her nightly prayer and wish, Cold and alone. No one can touch me. I feel nothing. I am the moon.

Outside the captain's door, there was more activity than usual. People were running, shouting, and screaming but the girl didn't pay much attention to it. It was another day. Another battle. If someone came to take her away, so be it. If she was going to be another person's prisoner, she's fine with it. If she was to be their slave, it would be nothing she hadn't experienced before. If someone came to end her life, even better.

The door finally swung open but the girl didn't move an inch. Her eyes were still fixed on the window. Even when she heard the sound of keys jingling and her cell door unlocking, she was unresponsive. Black boots appeared in front of her, just an inch away from her nose, and finally she blinked but otherwise, that was it. Her hair was brushed out of her eyes and for a second, she felt the warmth of a human hand. However, she remained motionless.

Only when she felt the keys get fit into her shackles did she jerk away and sit up. She stared wide eyed at the cell's new occupant and shook her head violently. She held her hands behind her head so that he couldn't get to the Sea Prism Stone. From the light of the moon, she could see that the man was wearing a fedora and his face was slim. He was squatting in front of her so she couldn't tell what he was wearing except that he had a white coat that hung over his shoulders.

"It's okay," the man said in a gruff voice but not unkindly, "I'm not here to harm you."

That seemed to not ease the little girl at all and she started to back away from him.

"Just let me-" he started to say, bringing the key closer to her again.

She let out a little gasp and turned her back to the man. She doubled over her hands, shielding him from her shackles. At her position, she didn't see the shocked expression from the man's face.

"Oy! What's going on in there?!" came a loud bark from outside. Soon, the whole doorframe of the captain's room was filled by a burly figure with wild hair. He, too, had a white coat draped over him.

"Vice Admiral Garp," the man in the cell said as he stood at attention, "I think I found another one."

"What do you mean you think?" Garp demanded, crossing the room with just three strong strides. He looked down at the girl and raised a very bushy white eyebrow that matched his beard and hair.

"I was about to verify it before you came in," the man said.

Then Garp saw what his right hand man, Bogard, was referring to. Stamped right at the base of the girl's neck was a burn mark. Even though her hair was covering up most of it, it had parted enough for Garp to see the hint of a circle with three marks at the top.

He knelt down but then much to Bogard's surprise, instead of moving her hair out of the way so they could see the full marking, the old marine brought all her hair to her back so that it cascaded down to her waist, hiding the scar under her curtain of hair.

"She is not a slave," Garp said loud enough for the entire ship to hear, "I, Monkey D. Garp, have confirmed it for myself."

The girl's head lifted up slightly but she kept her shackles close to her body. Then without warning, Garp scooped her up in his arms and held her to his chest. She blinked up at him, stunned from this sudden action as well as marvelling at how warm his whole body felt.

"Bogard," Garp ordered, without looking at her, "Bring the captain here."

The man in the fedora nodded his head, tilted his hat even further over his eyes, and walked out of the door, closing it behind him. Garp marched across the room and set the girl down at top of the captain's desk so that she was only slightly below his eye level.

He looked at her dirtied dress, which was more brown and grey than its original white, her skinny arms, and her sunken cheeks. She was shivering all over. Her head was bowed and her hair flowed over the desk surface. It was like she was tossed in a cell and forgotten for months.

The girl waited for the man to demand information from her but then he did another surprising thing. He pulled out a half eaten bag of rice crackers and held it under her nose. "Want some?"

She shook her head, despite the fact that her stomach was already caving in on itself.

"Are you sure? It's good," he laughed as he stuck his own hand in and grabbed a fistful. He shoved the crackers in his mouth and crunched loudly for her to hear. He kept eating and eating until finally the little girl reached tentatively into the bag and pulled one out herself.

She moved it under her hair and then Garp heard a soft crunch. The grin on his face got bigger. "Good, right?"

The girl nodded.

"Want to tell me your name?"

The girl shook her head.

"Do you have one?"

The girl shook her head.

"Do you want me to take off those shackles?"

The girl's head snapped up, her hair falling to the sides of her face and revealing her panicked blue eyes. Garp raised an eyebrow as he swallowed a mouthful of mushed up crackers. "I'm a marine. I mean you no harm. Do you realize that?"

There was a pause before the girl head bobbed down and then up.

"Yet you still don't want me to remove those chains?"

She nodded.

The door opened and Bogard returned while dragging the girl's most recent master by the collar. He was beaten to a pulp with a swollen eye, missing teeth, and rips all around his dark blue captain coat.

"Vice Admiral Garp," Bogard announced, "I've brought the captain."

"Close the door," Garp said, not taking his eyes off of the girl. When Bogard did so, Garp turned to glower at the defeated captain, "Carlyle the Trader, Captain of the Stray Dog Pirates, I'm charging you with an added offense of kidnapping. You are to go to Level 3 of Impel Down."

"Eh?!" the captain cried, "I didn't kidnap her from a Noble, I swear! I found her on another pirate ship. I was about to bring her to Sabaody and-"

"You bastard!" Garp roared as he punched the man hard across the face, lodging the man's head through the wall of his own room, "Why are you talking like this girl is a slave?! I don't see a slave here. All I know is that you had the balls to kidnap my granddaughter!"

"EH?!" the captain shouted as Garp pulled him back out of the hole he had just created, "Granddaughter?! She's your-?"

"I'm the one asking questions here!" Garp barked, "So tell me, why did you choose to put those harsh shackles on my beloved grandchild?! Answer me now or else I'll throw you down to Level 4."

"B-b-b-but if she's your granddaughter, shouldn't you know tha-"

"LEVEL 5!"

"AHHH!" the captain screamed, "It's her Devil Fruit power. She ate the Feel Feel Fruit!"

"The Feel Feel Fruit?" Garp asked.

The captain nodded fervently and hurriedly rushed to explain. "She's an empath. She projects powerful emotions everywhere. The first day we had her on board, everyone in my crew was in the fetal position and paralyzed with fear."

"I've heard about that fruit," Bogard said, "It's a rare fruit that is known to drive it's users mad. It's a double edged sword. The ones who possess that power usually lead very short lives."

Garp nodded and turned back to the girl, who was staring wide eyed back at him. "Leave us," he ordered, "And Bogard, once we get to Impel Down, I'm going to take a vacation."

"I will look after the crew in your absence," Bogard replied as he left with the captain in tow.

"Do you want another cracker?" Garp asked and the girl blinked back at him, "You should eat. Food is good."

The girl's mouth opened and then she shut it. She wasn't sure where to begin with this man. If she had her shackles off she could feel his intentions but that would open a whole can of worms. Not only would she absorb his emotions but everyone on the ship as well. Like Bogard said, it was a double edged sword.

"I said a lot," Garp said, "But the most important thing to know is that from now on you are my granddaughter, Monkey D….erm….Emmy! Yeah! That sounds good. If people ask, you were kidnapped many years ago and I have just managed to find you. Is that clear?"

The girl's lips parted again but, again, they closed almost immediately. She felt confused and frustrated. Was he trying to trick her? Gain her trust just so he can return her to Mariejois without any trouble? She had already experienced a miracle in escaping the first time. She doubted she was lucky enough to experience a second successful rescue.

Her eyes narrowed and her fists clenched in her lap. She refused to trust this man. She couldn't afford to. She did the only thing she could do to create some distance. She spat in his face.

Immediately, she regretted her decision. Why did she even bother? It didn't matter if she did go back to Mariejois. Her life was meaningless.

Garp's brows furrowed and his hands shot out towards her and the girl calmly closed her eyes, bracing herself for the inevitable beating. She was always beaten when she showed any signs of emotions. Anger. Courage. Even happiness. It always resulted in some sort of punishment.

Her eyes widened with shock when strong arms enveloped her and pulled her in tightly for a hug. "Good! That's good!" Garp practically shouted into her ear, "You still have some fight in you. That's good!"

His chest was big and his muscles were hard yet his hold was soft. The heat radiating from this man was nothing she had ever experienced before. The girl felt like she was being embraced by the sun.

"If you want to survive, if you want to live," Garp continued, "Then from now on, live as my granddaughter. Okay? If you want to live, call me gramps!"

Do I want to live?, the girl thought to herself, Am I not the moon? Cold and lifeless?

Then, to her surprise, she felt warmth in her own eyes and her vision became misty from her own tears. Why am I crying?

He must've felt the dampness on his shirt because he pulled back to beam down at her. "That's right. Cry! Feel everything you want to feel. Scream if you want to. Be mad at everything that has happened. Be happy that it's all over. Be sad that you had to experience terrible things. FEEL IT ALL! Prove that you are alive by being a feeling and fighting human!"

The tears started to flow down even more to the point that the old man became just a wavy blur to her. The girl no longer felt cold and numb. In fact she was just the exact opposite. She felt like she was on fire. The exhaustion in her body was gone and in its place was all of her emotions - fear, anger, relief, and something else. Something that she hadn't felt in a very long time. Hope.

She pursed her lips, feeling it quiver but unable to steady it. She blinked, trying to clear the tears away, only to have more fall out.

"Come on, say it. Prove that you want to live!" Garp shouted, "You can start a new life. You just have to call me gramps!"

Her fingers dug into the back of the old man. She squeezed her eyes shut and let her mouth fall open. "GRRRAAAAMMMPPPPPPPPPPPPPPPS!"

- Six Months Later in Mt. Colubo -

"ANOTHER ONE?!" Curly Dadan shrieked while her two sidekicks, Dogra and Magra, pushed her upright from the back.

"G-G-G-Garp-san," Dogra stammered, "We just got rid- er- I mean, we just said goodbye to Ace last year! You can't possibly expect us to-"

A menacing gleam from Garp's eye made them all stand up straighter and shut their traps. Then the glare vanished as quickly as it appeared.

"I figured you guys might be lonely so here's another one! Besides, I was actually supposed to drop her off a couple months ago but I got caught up with some work and didn't get a vacation until now. That's my fault. Bwahahaha," Garp laughed. He reached behind him and gently pushed out the girl that was using him as cover, "Emmy, this is Dadan. She'll take care of you while I'm gone."

Emmy took a hesitant step forward. Then she bowed politely to the female mountain bandit. Her bow was a perfect 90 degree from her waist with her arms straight and her hands pressed over each other. Her thick hair flowed down her back to her waist and was tied together at the bottom by a white ribbon.

She was wearing an adult man's button up and it hung all the way to her knees. The sleeves were folded up to her elbow, revealing the shackles around the wrist. The chains were cut off but the cuffs were still there. The shirt was cinched at the waist by a rope tied with a tight sailor's knot. The boots on her feet were obviously too large for her and looked identical to the one Garp was wearing.

"Please," Dadan pleaded as she sank to her knees, "Have mercy, Garp-san. I can't take on another one. It was a miracle we've survived thus far."

"Are you saying you'd rather survive in prison?!" Garp barked and Dadan immediately began to sweat. Then he grinned down at Emmy, "Besides, it's not like I'm giving you a baby to raise. She's only two years younger than Luffy. Plus, this one is very mild compared to the others. She's also quite handy around the house too."

Emmy nodded in agreement and she crossed the floor to the corner of the room where a broom and dustbin sat. She picked them up and began to sweep.

"Really?" Dadan said, eyeing her cautiously. Children were tricky and a handful. There was no way this child was that obedient.

"Like I said," Garp chuckled, "She's not the violent type. In fact, I expect her to learn how to read and write while she's with you."

Dadan practically swallowed her cigarette. "What are you talking about?! I can barely read and write!"

"Just the basic essentials is fine," Garp said, waving it off as if it was no big deal.

"Dadan! Look!" Dogra gasped as he tugged on Dadan's sleeve. He pointed at the other side of the room, where Emmy stood. The floor area around her was practically spotless and even the floorboards were shiny.

"So fast?!' Dadan shrieked.

"I didn't even know wood could gleam," Magma whispered with awe.

"Like I said. Quite handy," Garp grinned, "She managed to clean my ship in a third of the time it takes my men."

Dadan scowled. "Fine," she said disgruntledly as Emmy continued to sweep.

"Ah, before I forget!" Garp shouted suddenly. He crossed the room and he bent at the knees so he was eye level to Emmy. He took out a key and fitted it into one of her cuffs. Her eyes widened in panic and she dropped the broom she was holding. She started to pull back her wrists but then Garp put a heavy hand on her head, "Don't worry. I'm just giving you a little parting gift."

He lifted his hand but Emmy could still feel something weighing down on her head. He turned the key and the first of her shackles fell to the ground with a heavy thud.

"Touch it. It's fine," Garp said and Emmy obediently moved her hand to her head. Her eyes widened at the feel of a metal headband.

"I had consulted a specialist to make that," Garp said with a grin, "There should be enough Sea Prism Stone to keep your powers away without tiring you out completely. So...if you're ready, I'll unlock the last one."

"Gramps…" Emmy whispered as she studied his face for a moment. Then she lifted her shackled wrist slowly towards him. With a hollow clicking sound, her final bind was released. She closed her eyes and waited for a wave of emotions and voices to hit her but she felt nothing. Her eyes flew open and she looked wondrously at the old man.

"There!" Garp said as he stood back up and let out a barking laugh, "You're finally free!"

Emmy's lips began to tremble. It was the second time the old man had performed a miracle on her. Tears flooded her eyes and she threw her arms around his neck. "Gramps!" she whimpered, "Th-...Th-…"

It was the first time she had tried saying anything besides his name and Garp was ripe with anticipation.

"Thank-"

"OYYYYYYYYY! GRAMPS!"

"Watch out!"

Without warning, Garp's actual grandson came crashing through the window of Dadan's shack. Garp quickly covered Emmy's body with his to avoid any incoming glass shards.

"Oy! What are you doing here, Gramps?" Luffy hopped from one foot to the other. His sandals made a light smacking noise against the floor, "I wasn't expecting you for another 6 months at least!"

Thwack!

A hard Fist of Love cracked against Luffy's skull as the old marine ground his knuckles into the pained area. "Show some respect!" he barked, "A grandparent has the right to pop in anytime he wants! And be careful how you make an entrance! It was cool but it could've hurt Emmy!"

"That hurts!" Luffy complained as he squatted down and covered his growing lump with his hands. Then his head lifted when he realized there was someone new standing in front of him, "Eh? Who are you?"

"This is your sister, Monkey D. Emmy," Garp said.

"Oh, okay," Luffy said as he leapt back up to his feet and he grinned at the girl. "My name is Monkey D. Luffy. Nice to meetcha."

"WHAT?! That easy?!" their audience shouted and even Emmy's jaw dropped at how well the boy took the news.

Garp laughed, spotting her reaction, "See? I told you Luffy would be fine with it." Then he shot a stern look at Luffy. "Oy! Luffy. From now on, you're in charge of protecting Emmy. Don't let anything happen to her while I'm away. Got it?!"

"EHHHH?!" Luffy protested, "She can't fight for herself?!"

"She's your delicate sister!" Garp roared, sending another harsh punch to Luffy's head, "It's your duty to look after her! Consider it training to become a honorable marine."

"Who knew? Garp-san had a soft spot for girls," the bandits murmured to each other.

Luffy snorted in anger. "I already told you, Gramps! I'm not going to become a marine. I'm going to be the King of Pirates!"

"Idiot! I'm going to beat the foolishness out of you!" Garp thundered as he raised his fist but this time Luffy was ready for him and he jumped at the last second, towards the door. As he did, he extended his arm and grabbed Emmy by the wrist.

"Like I'd let you hit me for a third time. Idiot Gramps!" Luffy taunted as he stuck a tongue out at the old man, "Come on, Emmy! Let's get out of here! We don't need Gramps."

Emmy blinked in surprise but before she could even say anything, she found herself being slingshotted towards the boy's side as he burst through the door, running down the mountain side. He looked over his shoulder, not breaking his stride, and grinned down at her expression. "Shishishishishi. I ate the Gum Gum fruit. I'm a rubber man."

Emmy blinked back at him, unsure of how to react. Luckily, someone else did.

"LUFFYYYYYYY! HOW DARE YOU RUN AWAY! COME BACK HERE AND FACE ME LIKE A MAN!" Garp thundered, creating a large dust cloud as he chased after them.

"AHHHHHHH! He's coming!" Luffy shrieked. His eyes bugging out of his sockets at the sight of his raging grandfather, who was steadily catching up to him. He wound his arm around Emmy's waist and secured her even more to his side.

"Here, hold this," he said as he put his straw hat on her head then he put her hand over it to hold it down. Then he shot out his own hand to a large tree in the distance. "Ready, Emmy? IKUZO!"

Garp watched as his two grandchildren flew high into the sky. He had to throw a hand over his eyes to shield it from the blinding sunlight. He grinned despite wanting to tear his beloved grandson a new one. If anyone could bring some life back into that girl, it would be Luffy.

A/N: Special thank you to AmericanNidiot for your words of encouragement! If you guys haven't read A Sister Like No Other, you should! It's a great story!