Written as a gift for Sai (fishnomad on Tumblr) for the OP Secret Santa 2016!

Request: Anything with the Straw Hat Pirates! And if possible, including my One Piece OC, Humu, with them as one big happy family would make me super happy. Prompt-wise, anything about them bonding and having fun despite the bitter cold.

I decided to do a Christmas-themed Modern AU fic, I hope you like it!

Ace poked his head out of the living room in response to the crash in the hallway, letting out a fondly exasperated sigh at the sight of the shoe rack tipped right over, shoes scattered everywhere. His younger brother gave him a sheepish grin. With Ace there to help out though, it didn't take too long before everything was put back where they belonged. Ace stretched out the crick in his neck as Luffy pulled on his boots, this time without upending anything.

"You're heading out now, Luffy?"

"Yup, Sanji told me to pick up Zoro, so I'm going early!"

The older raven-head eyed him critically. "Are you dressed warmly enough? Here, wear this scarf and maybe you should put on another sweater? Are you wearing your thermals? That jacket looks a little thin…"

"Ace~" Luffy whined. "I'm gonna overheat…"

"Just let him be, Ace," a laughing voice called out. The two brothers glanced up at where Sabo was leaning against the doorway to his study, looking amused. "Anyway, shouldn't you be getting ready yourself? It's less than five minutes to six, Marco should be arriving any moment now."

"…Shit, you're right."

Sabo laughed as Ace sprinted back to his room to change. "Have fun at your party, Luffy. Send our regards to your friends, and tell Sanji thanks for the invite and sorry we couldn't make it."

"Okay!"

Bouncing out of the flat, Luffy almost ran smack into someone standing outside about to press the doorbell. The teen lit up with a grin at the familiar face. "Merry Christmas, pineapple-ossan!"

The blond smiled back. "Merry Christmas, Luffy."

Sabo held open the door as Luffy skipped energetically down the shared hallway towards the stairwell. "Ace is just getting ready," he told Marco. A loud crash echoed from further inside, making the pair wince. "Wanna come in to wait?" he offered as they shared a knowing grin, already wholly used to the situation.

"Thank you." Marco stepped gratefully into the warmth of the flat. "You're not joining us, Sabo? Oyaji and the others would love to see you."

"Normally I'd love to, but I've already got plans this time. Thanks for the offer anyway."

"He's got a date," Ace contributed as he finally emerged from his room, pulling on a beanie over his messy hair.

Sabo's pale complexion was instantly tinged with slight pink. "It's not a date, we just decided to catch dinner together before meeting with the rest of our co-workers for drinks later, since I wasn't going to be having dinner with you and Luffy anyway."

"It's a dinner date," Ace continued unrepentantly. "With a cute girl from work. Her name Koala and she has the 'prettiest blue eyes like the ocean depths' and 'the cutest little dimple in her smile'. This sap's words, not mine."

"I've never said anything of that sort!" Sabo squawked indignantly, beet-red all the way up to the roots of his hair.

"You were drunk off your ass and I have video proof. Yikes, will you look at the time, we've gotta go or we'll be late, Marco! Last one to the stairs is a plucked turkey!" Ace cackled as he nimbly dodged Sabo's attempt to tackle him, dashing away as fast as he could.

Marco just shook his head with a fond laugh at the brothers' antics before making his way after his hyperactive young co-worker. Sabo paused in his incensed swearing after Ace's long-gone back just long enough to bid him goodbye and a Merry Christmas.

Luffy beamed as the door swung open in response to his enthusiastic doorbell-ringing to reveal his friend's amused face. He tackled the taller man in a hug.

"SANJI! Merry Christmas! I went to pick up Zoro like you told me to. Is there meat!?"

The cook smirked around his cigarette as he let them both in. "Thanks for your hard work, Luffy. Merry Christmas to you too." He snagged the back of the younger man's collar before he could make a beeline for the kitchen following his nose. "Don't you dare. We're waiting for everyone to arrive before starting."

"Aww…"

"Oi, you didn't need to send Luffy, curly cook. I could have gotten here by myself."

"Right, and you would have gotten lost walking down a straight road and reached two hours later, and only because we'd all gone searching for your lousy ass."

The green-haired man made an annoyed noise. "There's nothing wrong with my sense of direction! The buildings move!"

"The day you don't get lost is the day Luffy turns vegetarian."

The mentioned youth, still caught in Sanji's relentless grasp, considered it for all of one second before wrinkling his nose. "Nah, that'd never happen."

"See, even Luffy agrees with me."

Zoro's eye twitched violently. "Damn you, curly cook."

"You want a fight, marimo bastard? Bring it on."

The battle that would no doubt have erupted was only stopped by two solid fists smacking unforgivingly down on the quarrelling idiots' heads. They clutched their heads simultaneously, groaning.

The owner of the fists let out an exasperated breath. "Can you two stop arguing just for one day!? It's Christmas, for goodness sake! Anyway get out of the way, you're blocking the doorway and it's freezing outside."

Luffy grinned widely. "NAMI!"

A dark-skinned girl popped out from behind Nami, smiling. "Merry Christmas, everyone."

"HUMU!"

Nami smiled as she stripped off her gloves in the warmth of Sanji's house. "I ran into Humu on the way."

"Nami-swan~! Humu-chwan~! Welcome to my humble home!"

"Tch."

"What was that, marimo!?"

"Yohohohoho, Merry Christmas, everyone!"

Everyone turned at the cheerful greeting to see the latest arrivals coming in through the still-open door.

"BROOK! CHOPPER! USOPP!"

"Merry Christmas!"

"Chopper, that reindeer antler headband is so cute!"

The brown-haired young boy wiggled at the praise. "That doesn't make me happy at all, ya bastards~"

At Sanji's suggestion, they moved into the cosy living room to settle down, placing the presents they had brought under the Christmas tree to be exchanged and opened later.

"The Great Captain Usopp once helped Santa to deliver presents to 5,000 kids when Santa's sleigh got stuck in the snow! He gave me the title 'Great Saviour of Santa Claus' in return for my mighty deed!" the long-nosed youth bragged, puffing out his chest.

Both Luffy and Chopper's eyes gleamed. "Really!? That's so awesome, Usopp!"

Sanji re-emerged from the kitchen balancing a tray of cups filled with amber liquid. "Here's some mulled wine for everyone to warm up. And mulled juice for Chopper."

The youngest member of their group beamed as he took the offered glass. "Thank you, Sanji!"

"That's lovely, Sanji-kun, thank you."

"Cook. Another."

"Don't just swallow the whole glass in one go, you uncouth marimo bastard!"

"Oh my, are we the last to arrive?"

"A SUUUUPER MERRY CHRISTMAS, EVERYONE!"

"ROBIN, FRANKY!"

"Robin-chwan! Here, let me take your coat and scarf."

The dark-haired woman laughed lightly. "Thank you, Sanji-kun."

"SANJI, EVERYONE'S HERE, MEAT!" Luffy bounced insistently.

The cook chuckled, finally relenting. "The food's all set up in the dining room."

"WOO-HOO!"

"That looks amazing, Sanji-kun!"

"You've suuuuper outdone yourself this year, cook bro!"

"Yohohohoho!"

"Let's eat!"

A few hours later, they were all stuffed full of turkey and roast vegetables and the whole array of dessert that Sanji brought out after the main meal. They lazed around the living room, splayed across couches and the plush carpet and any space they could get. They'd opened all their presents already, crinkled wrapping paper and ribbons scattered everywhere. The television played in the background, some classic Christmas movie that they'd all seen a thousand times. Sanji passed out refills of mulled wine.

Bolting upright, Luffy raised his glass high up in the air. "Hey, let's have a toast!" With matching grins and warm shared glances, they all did the same. Luffy's grin was the brightest of them all, the sun that lit up a cold winter's day.

"TO FRIENDSHIP, AND A VERY MERRY CHRISTMAS!"