The time skip is the most powerful weapon in a shonen manga's arsenal. When used correctly, a time skip can completely transform a series' world and characters while also introducing new antagonists and plotlines quickly and without much setup. Many shonen has tried, succeeded, and failed, including One Piece, the perennial shonen juggernaut. The series had its own time jump and pulled it off flawlessly.

Luffy and his Straw Hat pirates eventually took a two-year hiatus in the series, going their separate ways for a while. Before the Straw Hats split, they had just arrived at Saobody Archipelago to coat their ship in preparation for the journey to the underwater Fishman Island. They'd then enter the New World, the brutal second half of the Grand Line. The Straw Hats, however, were defeated by Admiral Borsalino, the marine Sentomaru, and Pacafista cyborgs created by the World Government. The Straw Hats give it their all against Borsalino, but they're exhausted after only narrowly defeating the first Pacafista together.

 

The Reasons Why the Straw Hats in One Piece Get Separated?

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However, because Borsalino was a Devil Fruit user, normal attacks simply phased right through his "light" body. All seemed lost until the Dark King, Rayleigh, appeared and rescued them by repelling Borsalino. However, the Straw Hats still had to deal with the second Pacafista. Realizing it was pointless to try to defeat Sentomaru and the Pacafista as they were, Luffy orders his crew to scatter and flee – a very out-of-character move for the rubber man, but one that demonstrates how dire the situation truly is. Unfortunately for the Straw Hats, things worsen when Bartholomew Kuma, the warlord modeled after by the Pacafistas, arrives on the scene, his intentions unclear.

Running is futile for the crew because Kuma's Paw Paw powers cause Roronoa Zoro, one of the crew's strongest and most loyal members, to vanish from sight with a single touch, terrifying the rest of the Straw Hats. The Straw Hats all seem to "pop" out of existence one by one, until all that remains is the rubber captain, mourning the crew he was unable to save. Finally, Kuma disappears Luffy in the same way he disappeared the Straw Hats, leaving only the words "we will not meet again...farewell." It's without a doubt one of the most difficult scenes to watch in One Piece, as the crew we've grown to love all vanish one by one, leaving us to wonder where they've gone. In a way, it’s scarier than if they had simply died.

 

Separating from His Crew Had an Incredible impact on Luffy.

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This scene signifies that it’s only going to get tougher from here on out for the Straw Hats. In fact, not counting his arena battle with the Gorgon Sisters, Luffy doesn’t actually win a single fight after separating from his crew. His head-on confrontation with Magellan results in him nearly dying from the warden’s poison. If not for his brother Ace, Luffy would have most certainly died at the hands of Admiral Akainu.

Determination and luck aren’t enough anymore for Luffy and The Straw Hats if they’re going to find the One Piece. They’re walking into the territory of pirates and marines who have decades more experience and skill than any of them. So, as much as all of them wanted to reunite, they all came to the realization that they needed to get stronger on their own.

 

Straw Hats from One Piece Trained Separately

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With this in mind, Luffy discreetly messaged his crew, signaling them to spend the next two years apart in order to train and grow stronger for their reunion on Soabody. However, simply becoming better fighters weren’t the only thing on each of the Straw Hats' minds. They were all developing skills pertaining to their roles on the ship as well. After landing in Torino Kingdom, Chopper, the Straw Hats’ doctor, took advantage of the island’s vast library of books on medicine and science in order to increase his scope of medical knowledge.

The cat burglar and navigator, Nami, spent two years on the artificial sky island, Weatheria, learning to use the sky wizards' advanced weather manipulating technology and studying the strange and unpredictable weather patterns of the New World. Even the exhibitionist cyborg, Franky, managed to find the infamous Dr.Vegapunk's research lab, where he studied the doctor's technology to give himself the perfect cyborg upgrade. It takes more than might to survive the New World and the resolve that Luffy and his crew showed by having the restraint to stay apart in order to grow stronger is what makes their eventual reunion feel so rewarding.