An: This is a marine!Luffy story. I hope you like it.
Update 28th June '17: I haven't really changed this chapter, but it is horribly formatted and the only one in the story that is horribly formatted and may thus be unappealing as a start to a story, so I'm updating it.
*** Sengoku's Office
Monkey D. Garp looked down at the small bundle that his son had left him not an hour ago.
"You'll be the best Marine there is." he whispered to the sleeping baby that was Monkey D. Luffy.
The Fleet Admiral of the Marines, Sengoku sat opposite his old friend Garp and observed the baby that lay on his table.
"So that's your grandson, Garp?"
The old Marine Hero smiled proudly in response.
" What do you plan to do with him?" the Fleet Admiral asked curiously.
"I'm going to send him back to Foosha village to live with the mountain bandits, they'll toughen him up and make him Admiral material!"
" Mountain bandits, do you really think that mountain bandits could raise a marine?" questioned Sengoku.
"No"
Garp paused to dig his nose and said, "Your point being...?"
Sengoku felt like face-palming at the logic of his old friend but continued, " So how will you make Luffy a Marine if you have him raised by mountain bandits!"
"Aah, I see what you mean... then I will raise him personally, he has to be a marine!"
Sengoku frowned, "Garp, how can you be a full-time parent when you have your Marine duties?"
"I'll take a 25-year leave, then." Garp replied, so determined on his grand-son that he would essentially quit his job for 25 years.
"How about you work part-time for us instead, that way you'll still be earning money and be able to return full-time after you are done training your grand-child."
"Sure!"
*** 12 years later
"232,233,234,235,236,237,238" Garp counted out as he sat on his Luffy's back while he did pushups.
Luffy was muscular for his 12 years of age and had unruly black hair. He wore a red vest and denim shorts.
Sweat rolled down his forehead as he slowly pushed himself up for his 239th pushup. On Luffy's 256th pushup, Garp's marine transponder snail rang.
"You're in luck, Luffy, you get a break while I'm talking," said Garp, picking up the reciever on the snail.
Sengoku's voice was concerned as he said, "Garp, we need you at HQ, there's been a breakout from Impel Down and-", he was interupted by Luffy who yelled in to the snail's reciever, " Thank you for giving me a break, Ossan!" while grinning his shit-eating grin.
That was until Garp's fist of love came down on his head and gave him a comically large bruise on his head.
***3 days of sailing later Dawn Island
"Dadan, I need you to keep Luffy for me, while I go and help at Marine HQ."
"Okay, I'll keep the brat, but no longer than a year, Garp, you hear me!" replied Dadan the bandit reluctantly.
***12 months later
Luffy and his new friends, Portgas D. Ace and Outlook Sabo were hunting tigers in the 3 of the young boys were monstrously strong but Luffy in particular with his Haki was even stronger than the other boys who were 3 years older.
After catching and eating a tiger each, the 3 of them were sitting and relaxing.
"I'm going to get some fruit for my desert, wanna come?"
"Oi, Luffy, get me some as well, I'm too full to move", said Ace.
"Get your own fruit, I'm only looking for my own desert!", said Luffy.
The young boy had wandered around looking for fruit to eat for a while before he came across a fruit he had never seen before that looked kind of like a huge cocoa bean.
It was very high up on a tree. Luffy used a combination of the Geppo that he was learning and grabbing onto branches to get himself to the top of the extraordinarily tall tree and eat the fruit.
As he devoured the entire fruit in a single bite, he tasted the horrible bitterness of a devil fruit and knew exactly what it was. Before he could wonder exactly which devil fruit he had eaten or what the ramifications would be, his hand that was holding onto a branch to keep him standing straight turned brown and liquidy and let go of the branch.
Luffy fell to the ground but strangely it didn't hurt all that much. Luffy stumbled/slithered back to where he knew his friends were. Upon seeing Luffy Ace's eyes widened, "Luffy!, is that you?" Luffy nodded. "What happened to you! you're all mucky looking... actually, that looks more like chocolate..."' At this Ace stuck a finger in the humanoid brown blob that was Luffy and licked the substance of off his finger.
"Mmm, yup, that is definately chocolate, how did you get yourself covered in chocolate?"
Luffy tried to say, "I ate a devil fruit", key word, tried.
His jaw melted into chocolate and didn't let him speak properly so what came out sounded more like, "I a a deii foo"
After concentrating for at least 20 minutes, Luffy managed to say, "I ate a devil fruit, from what I can tell probably some kind of chocolate devil fruit."
Ace burst out laughing, " You have the lamest power ever!" he said between gasps.
Sabo frowned and said, " We should probably take you back to Dadan."
The 3 of them head back to Dadan's base only to find that she was not there.
"Okay, let's take Luffy to Shanks then, he'll know what to do!"
Red-Haired Shanks was a pirate captain. At first Luffy has stayed away because his grandfather had told him that most pirates well the spawn of satan but eventually became friends with the pirate captain, though Shanks often teased him about what Luffy would do when he became a marine and had to catch pirates like Shanks because Luffy's dream was to become a Fleet Admiral of the Marines.
At this particular moment in time, Shanks was at Makino's bar, where he spent a lot of time.
Ace and Sabo rushed in with Luffy in all of his chocolately glory.
Shanks raised an eyebrow, "What the hell happened to Luffy?"
"Luffy ate a devils fruit!" replied Sabo, out of breath.
Whatever the 2 were expecting the red haired captain to do, they were not expecting him to start laughing, which he, of course, did. "By the looks of it you've eaten either the Numa Numa no mi or the Choco Choco no mi."
He stuck a finger in Luffy just like Ace had done earlier and licked it, "Yup, definately the Choco Choco no mi, that's a Logia class fruit, the strongest kind. By that time, Luffy had returned to look at least somewhat normal, if a little melty.
Garp chose this time to wall through the wall of Makino's bar. He stopped dead in his tracks when he saw one of the Yonko, Red Hair Shanks talking to Luffy.
He saw red, after all of his hard work, Luffy was being corrupted by a pirate. Garp pulled a cannon-ball out of nowhere and flung it at Shanks who noticed it at the last second with his observation haki and sliced it in half.
"Jii-chan!" screamed Luffy.
"DON"T YOU DARE CORRUPT MY GRANDSON, YOU RED-HAIRED BASTARD!" roared Garp looking extremely intimidating.
Luffy suddenly understanding why Garp was so mad said, "Chill Jee-Chan, I'm still going to be Fleet Admiral of the Marines!"
"YOU DAMN AKAGAMI, I'LL KILL YOU- wait what?"
"I'm not going to become a pirate" restated Luffy.
"Oh thank god!" sighed Garp.
"Vice-Admiral Garp, we need to leave soon!" said one of the Marine Soldiers who was flanking Garp.
"Okay" Garp replied before attempting to grab Luffy's hand, however when he did, Luffy's hand turned to liquid chocolate and dripped out of Garp's hand.
Luffy looked at Garp guiltily, "I ate a devil fruit." he said for what seemed like the hundredth time.
"Logia, the Choco Choco no mi", Shanks added helpfully then his face turned serious, "Luffy, do you still wanna be the Fleet Admiral of the Marines?"
"Of course" came the prompt reply.
Shanks took off his iconic straw-hait and handed it to Luffy, "This hat is very important to me, Luffy, when you become the Fleet Admiral, then return my hat to me, okay?"
Luffy put the hat on his head and was about to reply when Garp, using armament haki this time, grabbed Luffy by the shoulder strode out of the bar.
"I promise!", Luffy yelled as he was dragged out by his hat.
AN: I hope you enjoyed. This is my first fanfiction. I came up with the choco choco no mi on my own, it's a logia fruit for chocolate. Please review and all of that jazz.