Hey everyone. Another story with kid Luffy, but this one is in the Big Mom crew. I've done Strawhats and Whitebeard Pirates, so I decided I needed something new. I have not read or watched Whole Cake Island arc in awhile, but I did my best to keep characters and powers correct. Luffy is my interpretation of a likable child. not necessary how a five year old would act. Enough of my AN. Enjoy~

Update: just going to add that this story is cannon-divergent. And that not all relationships are the same as they are in the OP cannon world.

Chapter 1

Katakuri walked through the bland and somewhat cold slave auction house, heading to the amphitheater where the slaves would be bought, bored already. His crew had asked to be allowed to go, just to see. No one was going to buy anyone, no matter how they looked. So he allowed them to go, but then they wanted him to come, too. So he agreed to go with him. He'd probably get bored just sitting on the ship by himself. They told him it'd be cool if he bought a slave.

The captain had said no, that he didn't like weak willed people, and slaves were all broken. It's not like it was their fault, but he'd want someone who could actually work without cowering or being afraid of every little thing. It seemed annoying to have to train someone to work for them while they were terrified of him.

His siblings had had slaves before, and Katakuri never saw the the appeal was. They were all terrified, and it was hard for even the ruthless Katakuri to see the brands many of them had. Even though he didn't interact with them, he hated the Celestial Dragons. They were annoying and frustrating. Just made everyone hate the government more. He had killed one before, and it felt good. No one had stood up to him because he killed all that came after him. Big wigs didn't appear. His bounty had gone up from that incident.

He sat in the too-small seats with his excited crew, not really paying attention to all of the slaves being sold. They were all the same. Scared, crying or screaming to be let go. But all of them were bought. Katakuri yawned, adjusting his scarf after it had slid down a little bit. They were on the second to last slave, who was a large man, who looked scared and was shouting about wanting to go back home to his wife and children. But, of course, no one cared, and he was sold.

What came out next was a surprise to everyone in the amphitheater. A child with cuffs and a collar came running out and onto the stage. The slave traders chased after him, shouting at him to come back, but the little boy evaded them and jumped off the stage and began to run down the isle of the seats. The collar began to beep, so Katakuri leaned to the side and easily snatched him up and held him in the air. He was quite small.

"Lemme go! I not gonna be slave anymore!" he shouted in a high voice. He couldn't be older than five years old. And he was being sold as a slave, but apparently he wasn't going to go down without fighting. Katakuri found it interesting and amusing. And impressive. A slave that hadn't been broken, and also a child. With a will like that, this boy could become someone powerful. Katakuri could see potential.

Before he could think about what he was doing, he told the man coming to get the boy that he'd buy this one. The man suddenly looked terrified when he saw who had spoken to him. He began to shake, and the room went quiet after Katakuri's words. His crew looked at him in shock. So did everyone else. Katakuri gave off a threatening and hostile burst of haki that signaled that no one look at him.

He had said he wasn't going to buy a slave, and here he bought a child. But he had done it for a future strong ally. Well, that was what he thought at the moment.

The little boy still being held up in Katakuri's massive hand squirmed. "Too high! Lemme go!" the boy cried. Katakuri hoped he behaved better when he was out of those damn cuffs and chains. And not treated like a slave. There would be no potential if the kid was treated like a slave. What did he get himself into? But only a part of him was thinking that. The rest of him could see a kid who would grow to be strong.

"Alright s- sir, you can come pick him up right now if you'd like," the man said as Katakuri lowered Luffy back to the floor. Katakuri nodded, but grabbed the man's wrist when he began to drag the boy by his small wrist.

"He belongs to me now, so you will treat him as if he were not a slave," he commanded with a threatening glare. He didn't notice the little boy looking at him in shock. The meanies who had taken him before always tried to hurt him. He didn't like those people! But he didn't want them to laugh at him if he cried. So he never cried.

"A-alright sir," the man stuttered and lifted the boy up so he was standing before grabbing his hand and walked with him. "You will behave with him. Or die," the slaver said. The boy stuck out his tongue at him.

"Captain, what were you thinking?! He's a little child!" one of the men on his crew said, earning a glare from Katakuri. But they all thought the same thing. Was it just a rash decision, or not? Katakuri never made rash decisions, so there had to be some reason. The crew waited for their captain to answer.

"There's something special about him. I see potential in him," the large man told them. Everyone looked convinced now. Katakuri had a knack for being right about future events, even if this kid wouldn't be strong for years. No one said anything about the fact that someone would have to raise the kid.

Katakuri walked to the back of the building to where he was to pick up his new… charge? Student? Not slave… what should he refer to him as? Well, he should call him by his name first and foremost. There were slaves being taken away on leashes when he went to the back, and he saw the little boy having his hair forcibly brushed as he tried to get them to stop.

The massive man with the scarf walked up to the boy and the slavers trying to make him look presentable. Katakuri came silently, handing the 300,000 beris to one of the sellers. He had gotten the boy for very cheap. It was a good deal compared to the price of some other slaves who were sold and bought.

Katakuri said nothing as he took the key to the boy's shackles and paperwork about him. He only said to the kid to follow him, though it wasn't as cruel as the boy thought he would sound. Luffy hurried after him, suddenly curious about this man. "What is your name?"

"I Monkey D. Luffy," Luffy replied as he tried to keep up with the man's fast walking and large steps. Luffy had to run next to him. Katakuri noticed this and slowed down considerably. He wasn't surprised that this kid was a D. considering how stubborn he was on that stage, trying not to be sold. "Who are you?" he asked. Before Katakuri replied, Luffy told him that he liked his fluffy neck blanket.

"My name is Katakuri. And it's called a 'scarf'. People wear it when they are cold," Katakuri replied. Of course, if he were cold, he wouldn't have almost all of his torso exposed.

"Koori?" Luffy asked. The man repeated his name once again. "Ka-koori?" Said man told him to call him what he was able to say.

"Where are we going, Koori?" Luffy questioned. For some reason, he thought this man wasn't going to try to hurt him. Not like the other mean people who took him.

"We are going to my ship," Katakuri answered. Luffy asked what kind of ship. "A pirate ship."

Luffy gasped, somewhat startling the man. "Like Shanks?! Shanks is my friend and I want to be a pirate like him! It sounds fun!" Luffy said very loudly. Katakuri was very surprised to see this young boy knew another Yokno, and was friends with him. Well, Shanks must be very different than Mama if he befriended a child like this. He wondered how Luffy had been caught.

"I'm surprised. Akagami Shanks is very powerful. And he personally met a young child?" Luffy nodded.

"He give me his hat 'cause I gonna be strong and decide to be Pirate King, but I lost it…" Luffy said very sadly. "I hope he not mad at me…"

"You shouldn't say this having to do with the words 'pirate king' anymore. It's dangerous to say such things in my family," the sweet commander said sternly.

"...Okay," Luffy said grudgingly. He didn't want to be starved anymore. It was annoying! Everyone was so mean. "Are you mean, Koori?" he asked suddenly. The man didn't know how to answer. Yes, he was mean to some people, but for some reason, he never wanted to be mean to Luffy.

"No, I will not be mean to you, Luffy," Katakuri said as they reached his ship.

"Wow! It is a pretty ship," Luffy said, mostly to himself. "I can't swim, will you help me?" he asked as he looked up at Katakuri. The man reached down and picked up Luffy by the scruff of his shirt before sitting him in his large hand. Luffy was very small, even for a five year old. The man carrying the kid walked across the plank and onto his ship. He set Luffy down, who immediately ran off and around the ship to explore it. It wasn't a massive ship, but it also wasn't small.

The little boy ran around the ship, saying hi to everyone he saw or ran past. He really was small.

"Man, captain doesn't know what he's signed up for," the second most important member on the ship said with a laugh.

By dinner time, it was quite clear that Luffy was no normal five year old. He ate three servings of food that would fill a big adult like Katakuri. The chef had to make more food for everyone else since Luffy ate so fast. He had to sit on a small crate they put on one of the spare chairs at the table.

"Hey, you wanna know something?" Luffy suddenly said after he was full.

"What is it?" one of the crew members asked. They were entertained with Luffy, and how Katakuri sighed a lot when Luffy would go zooming from room to room.

"People in snow places never sleep." The others looked at each other. That really didn't sound right, but they humored him.

"Why is that?"

"'Cause they freeze to death," he answered, taking a sip of his water.

"That doesn't sound right…"

"Nuh uh, it's the truth!" Luffy countered.

Another one of the crew spoke up, saying, "Actually, he is right if he means sleeping outside. If you sleep outside in the snow, you could freeze to death while you sleep."

"See, told you!" Luffy said with a laugh. The others chuckled, while Katakuri just looked tired. His crew already seemed attached to Luffy, who was just a ball of joy after getting his chains and collar off earlier.

After dinner, Luffy was getting sleepy. This posed a question for everybody. Where would Luffy sleep? Right after the question, everyone on the crew but two had said "not it!". So it was now between Katakuri and one of the weaker members.

Of course Katakuri won rock-paper-scissors since he could see what his opponent would use, which irritated the man, but he didn't back talk or call him out on it. He didn't feel like being punished, physically or verbally, for going against the captain.

A pile of pillows was made for Luffy on the floor of the one room that had only one person in it, since the others were in bunks in another room. Surprisingly, Luffy was not a pain when he went to sleep. He stayed asleep the whole night, thankfully. He only woke up when his temporary roommate woke up and got dressed.

Luffy gasped, surprising the other man in the room. "I sleep good last night!" he cheered. "And on pillows! Thank you!" The pirate smiled.

"You're very welcome. Let's go eat, okay?" Luffy jumped up and went running out of the room, able to remember where the kitchen was, despite being so tired last night.

Luffy was cheerful for the rest fo the day, for a long time sitting at the front of the ship and looking at the sea. It was very pretty. Whenever he was on another ship, he was always locked up, and unable to look at the ocean. He wished he could swim in it without becoming so tired and sinking. It looked fun to swim.

Katakuri came over and stood next to where he sat, his feet through the bars and gave him his lunch. Luffy looked so happy to sit there, so he let the boy eat where he was. "Where are we going, Koori?"

Katakuri leaned against the high railing. "To my home island chain. It's called Totto Land. You'll be surprised to know everything is made of food. A lot of it is made of candy. Do you like sweets?" the man asked.

"I think so. I haven't had candy in a long time, but it must be yummy. I mostly get soup, and is gross!" Luffy replied sourly. Then he changed the subject. "I wish I could swim and not fall asleep and sink."

Katakuri frowned. "Luffy, have you eaten a Devil Fruit?" he questioned. Luffy was very young to have a Devil Fruit. He wondered, if he did, what kind he would have. Probably not something too powerful. Luffy looked up at him, confused. Devil Fruit? "It's a fancy fruit with lots of swirls. It gives you powers."

"Ah! The gross thing?"

Katakuri's eyes widened a little bit. Well, that proved he had eaten one. "Yeah. Did it give you any powers?" Luffy nodded.

"I can turn bright! An no one can hurt me 'cause of it. I no fthnk other 'masters' liked that 'cause I okay with them hurting me, though sometimes is annoying," Luffy said, sounding grumpy at the end of his reply. When he was asked if he could show it, Luffy replied that he didn't know how to work it. "But if you hit or spike me, I be okay."

Katakuri didn't particularly want to stab or hit him, but it was true he couldn't see any scars on his body even if he was once a slave. The commander took out his trident from his body and slowly poked Luffy with the tip. It went right through him, his body turning blue and crackling. Luffy had a logia type fruit?! How did he get a hold of one of those?

"That looks like lightning," he said.

"Koori is made of goo?" Luffy asked curiously.

"No, it's called mochi. It's a certain type of dessert," Katakuri sat down next to him, so much bigger than the little boy.

"You can eat yourself?!" he asked in awe. The man almost cracked a smile.

"Well, not myself specifically. I can make the dessert. Do you want to try it?" Luffy vigorously nodded his head, and watched in awe as mochi was made by Katakuri, and handed to Luffy, who ate it, though it was hard for him to chew because it was gooey. But it tasted good.

"That's yummy!" he exclaimed. "I wish I was made of food. Made of meat!"

"Luffy, you are made of meat." Luffy gasped.

"WHAAATTTT?!" Then he looked sad. "Well, I wish I was made of meat I could eat. I can't eat myself." He pouted. "I wanna be made of candy, too! Or just all food I want." He kicked his legs through the bars.

"Well, you should like your power. It's pretty powerful. No one can hurt you, and that's pretty impressive." He wondered if he sensed Luffy had a powerful Devil Fruit and that was the potential he saw in the little boy. But, with a power that could easily spark a fire, there would be no training on the ship. But that was fine; they were almost to Totto Land, and then home.

What would he tell Mama? He brought a kid back with him. How much lifespan would he lose? He found himself feeling upset that he'd have to be terrified of Big Mom. After all, even if he was brave in front of slavers and a big man like Katakuri, Mama was something else entirely. He'd never met someone who wasn't at least a little scared of her.

Line

Four days later, Katakuri's ship docked at Whole Cake Island, and was actually uncomfortable about people seeing Luffy with him. At least before they knew what he was doing with the commander. So he put Luffy in a pocket in his vest that was well covered with his scarf. After all, Luffy could fit in tight places. They'd found that out when the boy got trapped between a bed and the wall back on the ship.

Luffy did as he was told and stayed quiet and hidden in the pocket. Katakuri walked to one of the homes that stationed at Whole Cake Island, finding Brulee easily and asking her to go to the mirror at his place. She would be the first one to know, since he knew she wouldn't be mean to Luffy. She had always liked kids.

She was already at the house when Katakuri entered. "Is there something wrong, brother?" she asked, sounding concerned as she sat on the couch.

"I want to show you something before everyone else finds out," Katakuri said flatly, not nervous about what Brulee's reaction would be at all. But she became concerned. "Okay, Luffy, you can come out." And a little boy's head popped out of the pocket he was hiding in.

Luffy climbed out and onto Katakuri's waiting palm. Katakuri set him down on the large couch, which was sized for him, who was a lot bigger than Luffy. Brulee looked confused.

"A kid?" she asked, not understanding why he was there and why Katakuri brought him in the first place. "Why do you have a kid?!"

"I Luffy!" Luffy said, loud enough to drown out her surprised screaming questions. "Koori bought me!" Luffy explained. Brulee laughed.

"Koori, huh?" she asked. He glared at her. "So why did you buy him?" She was still shocked and watched as Luffy climbed up the couch onto the back of it. He looked around the room. It was big and there was big furniture all around it. He wasn't paying attention to either adults in the room. Instead, he leapt down from the top of the couch to the carpeted floor.

"Luffy, be careful," Katakuri said in reprimand.

"Okay!" Luffy called from behind the couch as he began to run around and explore the big room. There was a kitchen, too! But when he went up to the refrigerator, he definitely couldn't open the door himself. The handle was too high, and he wasn't the strongest five year old. He pouted, but not for long before he went back to the living room to explore.

Brulee looked at her brother like he was crazy. He had expressed concern about a young child. It was shocking. But she was still waiting for his answer.

"I see he has potential. He also has a powerful Devil Fruit," he answered, though Brulee knew her brother enough to see that was only part of the reason he took this kid to their home island without getting rid of him along the way for being an annoying child. But she didn't mention this. He would be embarrassed or get mad.

"What is it?" she asked, watching the boy climb onto the window sill and look out of the window. He gasped, seeing so much candy outside. It made him hungry.

"Lightning logia. He doesn't know how to control it, so I can try to teach him. I can see him being very powerful." Then he sighed. "How will Mama react?"

"She'll probably take some of his lifespan. When are you going to tell everyone? Do you need clothes? Furniture? Shoes?" Brulee asked, somewhat excited. Luffy wasn't Katakuri's son, but he would be staying with him for at least a little while. And Brulee was good at making clothes.

"I'll have to introduce him to Mama before the tea party, and then I can show him to everyone else there. But don't tell anyone about his Devil Fruit. Alright? And yeah, clothes and shoes would be great. His current clothes aren't exactly presentable," Katakuri finished, looking over to Luffy, who was for some reason trying to do a cartwheel. And failing, but he kept trying.

"I'll get started today for him to be presentable when you bring him to Mama." Then she looked to Luffy. "Luffy?" she asked. Luffy looked up and hurried over to them. "My name is Brulee. I'll be making you clothes and shoes. What is your favorite color?"

"Red! I like red," he told her.

"Oh, try and make him something appropriate for the tea party," Katakuri said.

"Alright, well, I need to take his measurements, too. Luffy, would you like to come with me to the mirror world?" Brulee asked.

"Yah!" and he ran to her. Brulee said goodbye to Katakuri, who was preparing himself to talk to Big Mom.

Luffy gasped as Brulee took him through a mirror and into a world of checkered walls and thousands of mirrors. He ran over to one and looked inside, then to another one, and another. Soon he was looking in every mirror he was tall enough to see through, announcing what he saw.

"Brool, when do I get to see the candy places?" Luffy asked as he skipped over to her. "It looks yummy!" he said as he now walked next to her.

Brulee turned to walk towards the mirror she was leading Luffy to, and told him that he would see them soon, but couldn't eat the houses because people lived there. "Would you want someone to eat your house?" she asked.

"No, that would be mean," Luffy said. "Are we going through a mirror again?"

"Yes, we're going to my room to get you some clothes. The clothes you are wearing are smelly," Brulee said as they passed through the mirror. Luffy smelled himself. He agreed with her. He didn't smell good. So she had him stand on a stool since he was a lot shorter than her and took his measurements. He was very small, and she asked how old he was.

"I five."

After she took many measurements of his body and for his shoes, she took him back to Katakuri's mirror and they both sat on the couch. Brulee asked him about himself. Trivial things like his favorite food and animal. When she asked about his family, it was brief since he hadnt seen them in a long time.

Line

Katakuri stood in front of Big Mom, who was stuffing her face with live cupcakes, as she listened to how he carried out the mission he was sent to, which involved painful murder. He completed it perfectly, and no one was hurt. Well, not that she really cared about anyone getting hurt. Especially people as low as crew mates.

"Why do you look uncomfortable, Katakuri?" she asked suspiciously. "Is there something else you want to tell me?"

"I bought a slave on my way back to the islands," he said simply.

"Oh? What are they like? When are you going to introduce me?" she asked curiously. She never pictured Katakuri wanting a slave.

"He's a child. I bought him because I saw potential in him. Then I found out he's a logia fruit user. I would like him to be presentable in front of you, so I'd like to wait for you two to meet until he has clothes and shoes. I'll ask Brulee to make him some garments," he explained. He knew Mama would be upset if she knew someone else knew before she did.

"Interesting... How old is he?" she questioned. She was interested in this boy if Katakuri had been enough to buy him.

"He is five years old. And a 'D'." Big Mom looked at him like he was someone she'd never met. Granted, suddenly taking in a five year old child was surprising for someone like Katakuri.

"Name?" she demanded. She was not pleased that he bought a child that he'd have to train and take care of. It'd better not interfere with his work for her.

"Monkey D. Luffy." It was as if Katakuri could read his mother's mind, as he said, "I will not let taking care of him interfere with business and missions." She raised her chin at him in what looked like a challenge.

"It better not, or he won't be here anymore," she said with a cold laugh. "You can go." Katakuri hurried out of the room and the whole building, scowling. He was almost never angry with Big Mom, but what she said pissed him off. People he passed moved away from him with the angry feeling haki coming from him unintentionally. No one ever criticized her for having over 80 children. But then again, Katakuri wasn't the one in charge. He wasn't a Yonko. But it still angered him. He wouldn't let her kill him, which he knew was what she threatened.

Luffy was five, and a five year old isn't the most organized age mentally. Katakuri hoped that he could get Luffy to behave and not run around the palace or tea party like a crazed maniac. Or just a hyper five year old. He didn't know if giving Luffy as much sugar as there was going to be there was a good idea.

Katakuri had been with his younger siblings while they were children, and when many of them ate as much candy as they could, you couldn't get them to sit down, and then they suddenly had the inevitable crash and fell asleep.

Luffy was hyper a lot already, and it seemed more so when he was introduced somewhere new.

When he got back to his home, Brulee and Luffy were there, Luffy napping on the couch and Brulee sewing on the window seat. Katakuri knew that Luffy was a heavy sleeper when he napped, so he had no problem with talking to Brulee about what happened.

"So? How'd it go?" the sister asked.

"Not good. She's not pleased. And if he interferes with business, then he's gonna go," Katakuri said, not saying what Big Mom meant, but Brulee knew what he meant. She sighed. "How'd he behave?" he asked.

"He was very excited about the mirror world. More than a couple times he looked into bathrooms and I had to tell him to not look, but other than that he was fine. He stayed still while I did the measurements. If you ask or tell him to, I'm sure he'd behave fine. The clothes will be done quickly, but the shoes might take longer, so I'll make him sandals, which will be easier to make."

Katakuri sighed. He actually didn't want Luffy to look presentable anytime soon. He had no idea how Luffy would react to Big Mom. He didn't like it, but he hoped Luffy got scared. For his own safety from Mama. She would be furious if he wasn't scared of her and she wouldn't be able to take any of his lifespan.

But he was a 'D' and everyone had heard about them supposedly being determined and even fearless. He looked to Luffy again, suddenly feeling a little bit guilty that he'd taken Luffy to this dangerous place in the first place. He might have been able to just drop the kid off at a shelter in some big city on an island. But it was only because of Big Mom that he wished he hadnt taken him in. Katakuri actually did like Luffy. And his crew and now Brulee all liked him. He was really an easily likeable boy. He hoped Big Mom felt the same when she met him.

The chapters are a bit long, so if anyone wants me to shorten them by cutting them in half, tell me. It has over 4,000 words in almost all of the chapters, or longer.