In episode 405 of the One Piece anime titled “Disappearing Crew - The Final Day of the Straw Hat Crew”, the Straw Hats were utterly defeated at the hands of Warlord Kuma, the Tyrant. Kuma used his devil fruit prowess to send the Straw Hats flying, forcing the crew to split up.
Eliminated Friends - The Final Day of the Straw Hat Crew - One Piece (Season 11, Episode 24) | Apple TV. S11 E24: One by one, the mighty paw-print of Bartholomew Kuma makes the Straw Hats disappear until only Luffy remains.
So far, Nami, Robin, and Usopp have all chosen to leave the crew in the past, before returning. Additionally, Chopper and Sanji have been coerced by third parties to leave the crew despite their wishes, with Chopper returning soon afterwards.
While One Piece has many superb side characters, Big News Morgans just proved why he is the best of them by betraying Luffy and his crew. This may not seem like an action that would endear Morgans to One Piece's fans, but his reasons for doing this give him a delightful layer of complexity.
Because of threats to the life of his mentor, Zeff, and the other Straw Hat Pirates, Sanji abandons Monkey D. Luffy and his allies to once again assume his position as a prince of Germa Kingdom.
Nico Robin
She stayed with the crew until after the events of the Water Seven arc, when she was found out by the CP-9 and coerced to turn herself in to help the World Government read the Poneglyphs. She initially refused, but agreed to leave after the CP-9 threatened to launch a Buster Call against the Straw Hats.
The reason Robin “betrayed” the Strawhats is because CP9 had permission to order a Buster Call on the Strawhats. This is an overkill arrangement whereby five vice-admirals arrive with ten battleships and destroy the target with extreme prejudice.
That said, there is one crew member who stands above the rest in terms of loyalty to Luffy: Roronoa Zoro. The Straw Pirates' first mate has proven his loyalty on numerous occasions throughout the series, even putting his crew mates' well-being above his own life.
Out of all the Straw Hats, Usopp is easily the least loyal. Not only did he nearly abandon the heroes amidst their darkest hour at Dressrosa, but he also fought Luffy directly for the rights to the Going Merry.
Jinbe. While this might change after One Piece Chapter 1057, Jinbe is currently the final recruit for the Straw Hats Pirates. The Fish-man serves as the skilled helmsman of the Thousand Sunny.
Luffy and the crew follow her, and discover that she is working for a dangerous Fishman pirate named Arlong.As an abridged version of the Arlong Arc, the special follows the same general plot. Nami leaves the crew after the Baratie Arc to go back to her village.
Robin also seems to be very devoted to Luffy, as he is the only person whom she wants to get stronger for. This shows how great her dedication to her captain has become after being rescued from Enies Lobby. Upon learning of Ace's death, Robin was very shocked and became greatly concerned about Luffy's wellbeing.
Although Yamato doesn't have a set role, for now, Oda can easily create one for him. Fans already saw this with Jinbe, who was made the Helmsman of the crew upon joining. Yamato needs Luffy's approval to join the crew and, once he gets it, he's officially going to be the 11th member of the Straw Hat Pirates.
Roronoa Zoro learned how to imbue his swords with Armament Haki during the two-year timeskip when he trained under Mihawk. Thanks to his guidance, Zoro has become incredibly good at this skill.
Sanji - Training With Ivankov
One Piece's Sanji was sent to the Kamabakka Kingdom, an island inhabited entirely by okama that happened to be the home of one of Luffy's newest allies, Emporio Ivankov.
Short Summary: Zoro was sent by Bartholomew Kuma to Kuraigana Island, the same location that Perona had been sent to.
As far as canon story is concerned, Luffy won't marry Boa Hancock.
Throughout his journey Luffy has made strong bonds with numerous women. At least two have fallen in love with him, Alvida and Hancock, whilst another two have become enamoured with him, Rebecca and Shirahoshi. Nami, Robin and Vivi all share close and deep bonds with Luffy and have become some of his closest friends.
Usopp After Wano
Usopp remains to be the weakest member of the Straw Hat Pirates.
Yamata is going to become the 11th member of the Straw Hat Pirates soon. We thought she will become one by the end of the Wano arc, but unfortunately, she stayed to help Momonosuke and the others raise Wano back to glory again. But Yamato is confirmed to be the unofficial 11th member of the Straw Hat Pirates.
Zoro trusts Luffy implicitly and always follows his decisions whatever the consequences, acknowledging it as a captain's decision, which a crew must carry out without question. When Zoro first joined Luffy, he made it clear that he would turn on or even kill his captain if he ever stepped between him and his dream.
Unlike Nami, there isn't an obvious love interest
In particular, her possible love interests include the likes of Luffy and Sanji.
Weaknesses: Robin cannot swim and becomes immobilized if more than half of her body is covered in water. She feels anything her extra body parts feels, as she will gain damage to their body if the extra limbs are attacked.
Nico Robin was born on the island of Ohara and came from a family of archaeologists. Her mother, Nico Olvia, went out to sea to find the True History when Robin was two years old, leaving her in the care of Olvia's brother and his wife, Roji.