American Nidiot: Whoops, my hand slipped and I made another One Piece fanfiction, focusing on the older sister of Monkey D. Luffy! -throws confetti-

Ignoring the shocked looks of the Marines and his crew, Luffy stared curiously at Garp, watching as the old man looked ready to mention something else. "Then there's Rain," the old man mentioned, continuing to fix the wall that he busted down for his own amusement.

"Wait, Rain's still alive?!" shouted Luffy, looking surprised about this bit of information that fell into his lap.

"Of course she is! If you're still kicking, then Rain is, too! After all, she's the one that got all the brains, on top of being a D.! Have a bit more faith in your own sister, Luffy." Garp honestly couldn't, for the life of him, figure out how Luffy's mind worked at times.

"You have a sister?!" shouted Sanji, looking as surprised as the rest, and looking ready to keel over any second.

"Yup. Sure do. Rain's my big sister!" Luffy beamed, smiling fondly as he remembered his beloved sister. "She easily kicked both mine and Ace's butt when we were all kids. Rain's normally the one that busted us out of trouble, and the calmest of us all. Sis gets super scary when mad, though! I remember when she scared Shanks after I ate the Gum Gum fruit, because she was so mad." The Straw Hats stared in awe at the loving way their captain talked about his sister. "Rain can even kick Grandpa's butt if she wanted to!"

"Watch your mouth, boy! Or do you want another helping of my Fists of Love?!" shouted Garp, scowling at his grandson. "Otherwise I won't give you the gift she demanded I give you."

Luffy sprung towards his grandpa, grabbing the lapel of his coat, and got into his face. "Rain gave you something to give to me? Where? Gimme, gimme, gimme!"

Garp punched the rubber boy in the face. "Calm down, boy!" rummaging around in the inner pocket of his coat, the Marine Vice-admiral pulled out a wrinkled envelope.

Luffy frowned and snatched the envelope out of Garp's hand and tried smoothing it out on his chest, a bit displeased with how his grandpa mishandled something so precious. Once happy with his handiwork, Luffy carefully opened the envelope and pulled out a blank scrap of paper. It looked similar to the one Ace gave him back in Alabasta. Next was a letter. Unfolding it, Luffy gazed at the familiar fancy loopy handwriting.

"Luffy, I hope you haven't forgotten me after the few years apart! Well, knowing you, I wouldn't be all that surprised. Probably have too many exciting adventures or delicious food, that you forgot about me, or never cared to mention me to your crew (just like with Ace, I bet). Bless them for being able to handle you, little brother. You're such a handful, you know? Haha, but I wouldn't have it any other way, to be perfectly honest. Oh, and congrats on your bounty! Look at you, a big shot pirate captain now… Can't say I'm anything but proud. And if Gramps is still there, tell him to go wear a frilly dress and have a rice cracker tea party."

Garp cackled when Luffy told him exactly what Rain wanted him to, finding his granddaughter's resentment of him forcing her to wear dresses as nostalgic.

"You're probably wondering where I am, or what I'm doing seeing as I haven't made waves since leaving Dawn Island. Don't frown, cause I know that's exactly what you're doing," Luffy pouted instead, realizing his sister was right, "and don't pout either, you're not 7 anymore. Always smile, because that's just the type of people we are in the end. Anyways, for the most part I'm keeping my head down and doing things that could cause trouble for Gramps and the World Government in general, however once the time comes, you can bet that I'll be out there having my own adventures. When that time comes, I promise we can have a fight to see who is the strongest between us. Until then, keep causing trouble, and keep getting stronger. I look forward to the next time we meet, little brother, and I'm interested in meeting your crew. Until then, may there always be wind in your sails that'll carry you to your next grand adventure; Monkey D. Rain."

Reading, and then rereading, the letter, Luffy tucked the letter safely into his pocket before handing Nami his hat and the small paper scrap. "Nami, can you sew this on my ribbon like you did with Ace's? Except can you put it on the opposite side?" he asked, looking his Navigator in the eyes.

She gently took the items and nodded, quickly setting to work on sewing the piece of paper on the ribbon. Sanji, on the other hand, still looked ready to have a heart attack over the news that Luffy had an older sister. "Why haven't we heard anything about you having an elder sister, Luffy?" questioned Robin. "After all, we know that you have an older brother, so why not mention anything about your sister?"

"Because no one asked, so there wasn't a point in mentioning Rain," replied Luffy, calmly watching Nami as the tangerine-haired Navigator skillfully sewn the paper into the inside of his ribbon.

"More like he forgot he had a sister due to all the adventures he has had up 'til now," Garp added while picking his nose. "Rain disappeared four years ago, and if she doesn't wanna be found, then you won't ever find that girl unless she wants to be found."

"Sis' a master of hide-and-seek!" Luffy laughed, placing his hat back onto his head, and beamed his brightest smile at everyone. Robin smiled as well, looking fondly at her captain as he beamed brighter than the sun.

"You must really admire your sister, Captain," commented the archaeologist.

The rubber boy nodded at the woman, his dark eyes sparkling with admiration at the mention of his sister, just like when he talked about the history of his beloved hat. "Yeah. Rain helped Makino raise me before we were sent to Mt. Corvo to live." Turning his head, he stared eagerly out the window. "I can't wait to meet Sis again! Maybe if I annoy her enough, she'll agree to join my crew! Shishishi~"

American Nidiot: Yup! Here is my new OC, Monkey D. Rain! She is 6 years older than Luffy, making her 23 pre-time skip! Ahh~

Also, this story will be more of an AU because Rain is Luffy's big sister.

Also *SPOILERS AHEAD* she will probably come off as Mary-Sue because she can use Haki, and then there's her Devil Fruit, and being older than Luffy, she is a bit stronger, too. Just like how Ace and Sabo are stronger than Luffy pre-time skip. Moreover, unlike Luffy, Rain spent time with their father, and he's taught her a thing or two. *END SPOILERS*

I have the first two chapters (meaning this one and Chapter 2) already typed up, and am working on Chapter 3 as I'm typing this section up.

There will be a time skip between each of these three chapters, along with some Point of View/writing change. This chapter and 2 are written in 3rd person for a reason, while chapter 3 and on-ward are in 1st person and will mostly be seen from Rain's point of view unless otherwise stated (cause we gotta have moments of seeing the story through Ace, Luffy, and some other's eyes~).

Yeah, it'll be marked as romance though I will mostly focused on a more "family/platonic relationship" vibe mostly. And the pairings will be Law/Rain (main), and Ace/OC (side).

Now that that's all said and done, please leave reviews! I want to see if it'd really be worth the effort to write and post more chapters if there are enough people interested.

And in other news, I am currently working on a few other One Piece fanfictions! Here are the titles to look out for!

"You Are My Sunshine" Ace/first mate!OC that'll take place at the beginning of Ace's journey and will continue to the current time-line so it'll be AU!

"Once Upon a Dream" (title might change) Luffy/water faery!OC (will try and make it semi-realistic).

"Of Angels and Surgeons" which is another Law/OC fanfiction! With the OC being the captain of her own crew, the Nirvana Pirates!