A/N: I do not own One Piece. Only thing I own is Rei (my OC).

If you want to read Rei's backstory, how she became a Straw Hat, and her relationship with Zoro, please read my fanfic named "Zoro and the Mask" to get the details. I'll fill in the blanks as much as I can throughout this story but if you really want to know about Rei, please check it out! :)

(Currently, this story is on hiatus until the anime progresses a bit further in the Zou arc but I fully intend to continue writing this story!)

This takes place starting from ep 579 (Punk Hazard) and keeps going from there so please do not read if you are not there yet in the anime. There, you've been warned. NOW ENJOY!

Chapter 1 - Ikuzo! Rei's First Straw Hat Adventure

It was not a good day to be sailing. The sea was dark and stormy but that didn't bother Cogan Reia, the newest crewmember of the Straw Hat Pirates. No, what bothered her was the thunder. It scared her but she tried very hard not to show it. She was pretty good at keeping her emotions in check.

She still secretly flinched, though, whenever thunder clapped especially loud. She was used to the sunny, summer weather of Beffi Island, where she had grown up as a Royal Tactician and Commander for King Tannenbay and the Beffi Army.

Rei, as she preferred to be called, was a twenty year old genius that had been hidden away from the eyes of the Navy due to her blood ties to high profile pirates. Her uncle was 'Red-Haired' Shanks and her father was once a crew member of Gol D. Roger. She even had to disguise her own gender to throw the Navy off her scent.

Through a random chain of events, Rei found herself being assisted by the Straw Hat Pirates to save her and her family, which ended up with her on the run from the Navy with a very respectable bounty of 60,000,000 bellis. She had been sailing on the Thousand Sunny with this motley crew for about a week now and she was experiencing, for the first time, bad weather on a pirate ship.

If there was a god, Rei was sure he wasn't too happy with her and her nakama since the waves thrashed violently around the Thousand Sunny and the rain poured down like a cold shower on it's passengers. She held tightly onto the railing on the side of the ship as the Sunny rode out a very high wave. For a moment, it seemed like they were flying.

The wind was strong, making her thick black cloak fly out behind her. It was too strong to keep her hood up and her braided red hair waved behind her in the wind like a thick flag. Thankfully, her white and gold mask kept her face shielded from the rain so her vision was clear... Well, as clear as the night sky would allow it to be.

She looked over at Roronoa Zoro, who stood on the rigging that connected the deck to the top of the mast. His one good eye glared back at her as the muscles in his left arm bulged from his strong grip on the rope, keeping him in place. Pay attention and don't get yourself thrown overboard, the green haired swordsman seemed to say with his scowl.

Rei did not respond. Instead she moved on and roamed her eyes over the rest of the Straw Hats. Tony Tony Chopper was clutching the bottom of the same railing as Rei with all four of his limbs. 'Cyborg' Franky was at the helm, steering his prized ship. 'Cat Thief' Nami and 'Black Foot' Sanji were near the doorway to the kitchen. Nami stood in the rain wearing her pink raincoat while Sanji stood inside his domain, as the cook preferred to keep himself dry. Everyone else was spread along the lawn deck, trying not to lose their balance.

Their captain was leaning dangerously over the edge as he hung tightly to a rope ladder on the other side of the mast, near the top of the sails. "Go!" Monkey D. Luffy shouted excitedly as the wind whipped the sides of his red shirt behind him.

"Oy! Oy! Oy! Do you think this is the best decision?!" Usopp the sniper cried as the Sunny lost its momentum and they began to fall back down to the water, "EEEK! We're going to crash!"

As they landed with a giant splash, only a handful of the pirate crew stood their ground. Rei had to move her leg slightly to the left so that Chopper would roll into them, stopping the reindeer from tumbling any further down the deck, while Sanji helped Nami to her feet and Franky righted 'Soul King' Brook up after he toppled into the mast. Rei worried about the damage the Thousand Sunny was taking while she helped Chopper to his feet.

"Are you okay, Dr. Reindeer?" she asked.

"I'll be fine," Chopper whispered back as his eyes swirled with dizziness.

"Look! What's that?!" Nami cried as she pointed ahead, making Rei forget about the reindeer for a moment.

The Straw Hats turned to see where their navigator was referring to and their eyes widened at the sight.

"A red sea?!" Usopp shouted in disbelief.

Indeed, it did look like the water was red but as Rei looked further back, she noticed what had caused the color change.

"It's a volcano! Look! It's erupting," she called out.

An active volcano sat in the distance on the edge of an island. It was spewing out lava and ash high into the air and down into the water below. The Straw Hats watched with a mix of fear and awe as the red molten rock slid down the slopes of the mountain and remained burning even in the water.

Behind her mask, Rei's eyes sparkled both from the flickering flames of the water and out of excitement. She had read about volcanoes and she knew the geology behind it but to read something in a book and to experience it in real life were two very different things. The more time she spent out at sea with her nakama, the more Rei realized it.

"Let's go to that island!" Luffy immediately shouted, to the dismay of the rest of his crew.

"Wait a minute, Luffy!" Nami interrupted as she showed him her log pose, "None of the needles point to that island!"

"Impossible," Rei said as she ran over to look at the navigator's wrist.

To her surprise, Nami was right. All three of the needles were either pointing in another direction or spinning uncontrollably. Rei had never seen or heard of this phenomenon before.

"Finally, something the Know It All can't explain," Zoro quipped as he came down from his rope ladder.

Rei ignored the swordsman and looked back at the volcano. "Know It All" was Zoro's nickname for her ever

since they met and he seemed to be unable to call her by anything else.

"How it can not be pointing at anything?" Rei asked Nami, who shook her head in response.

"Let's go to the island!" Luffy shouted again, "The volcano looks like fun! Let's go!"

"We can't get any closer!" Nami yelled back, "The sea is on fire."

Rei went back to the railing and leaned over to look at the flames that blended with the water, mesmerized at the sight. She had never seen anything like it before. She rarely got to leave Beffi Island and when she did, she always stayed inside the ship to keep herself away from prying marine eyes. The fire flickered and

her green eyes shined in amazement.

She quickly pulled out a green notebook and made a note under her "Like" list.

"Flames in water," Zoro read out loud as he peeked over her shoulder.

Rei quickly closed the notebook and she turned to look at the swordsman. "Social protocol says

that it is rude to invade someone's personal space," she said flatly.

She had no friends growing up and limited social interaction so Rei's only source for etiquette and propriety were from outdated books she found around the house. Of course, that made her oblivious to common social signals and could often cause her to be in very awkward situations.

To Usopp's mischievous delight, he had discovered that if he told Rei that if something was socially acceptable to do, she'd do it. He had found someone almost as gullible as Chopper.

"How long is your list now?" Zoro asked with a raised eyebrow, ignoring her comment on decorum as he reached over to take her notebook.

Her list had grown considerably since they had left Beffi Island. She grew up without a normal childhood, with only survival and protecting her father as her goal. Because of that, she had no time to develop a dream of her own. Per Nico Robin's suggestion, she started to keep a list of things she liked and disliked to help her out on her journey of self-discovery with the Straw Hat Pirates.

Now, the green haired swordsman wanted to read her list and he was leaning incredibly close to her to get to it. Rei could have easily ducked away, as she was incredibly fast, but for some reason, she didn't want to.

She started to say something but then a sound of a man crying suddenly rang out. Whew, saved by the bell, Rei thought as she darted away from the swordsman and ran towards the cries.

Damn it, Zoro cursed to himself as he watched her go, Ever since Robin convinced her to write in that stupid notebook, it seems to be all she ever does.

Zoro had noticed over the last few days that every time the cook gave Rei a new dish to try, she'd flash him a smile and write it down in her stupid list. He wanted to know what else was on that list. It also annoyed him even further that he even cared in the first place, which fueled his negative feelings on the notebook even more. It was a vicious cycle.

He sighed and followed the rest of the crew towards the sound. He'll get that notebook one day. Yes, he'll also take great pleasure in cutting it up when he was finished reading it.

"Wahhhhhh!"

The male cries were getting louder and louder. It was coming from the transponder snail in the kitchen and the Straw Hats all clamored in to see who could possibly be calling them. The snail was bawling loudly with rivers of tears flowing out of its eyes.

"Hey, what's this?" Luffy asked baffled at the sight, "Does it have a stomach ache?"

"Idiot," Sanji said from the other side of the kitchen, "That's an emergency signal. Somebody's calling for help."

"Oh, let's pick it up then," Luffy said reaching over towards the receiver.

"Wait, Luffy!" Robin cried out, stopping the captain's hand in midair, "More than 50 percent of emergency signals are fake."

"Yes," Rei agreed, as she stood beside the raven hair beauty, "The Navy often uses it as a trap."

"If the line is tapped, they'll find out where we are," Robin added.

"I'm so glad you two are here," Usopp said as he put his arms around both women and sighed with relief, "Hey, Luffy you have to be careful-"

Catcha.

But it was too late, their captain already took the receiver and was starting to speak.

Special Shoutout to my Beta Reader: SolaceActor. Thank you for being my second pair of eyes.