BON KUREI
Mr. 2 Bon Kurei, is a former officer agent of Baroque Works and an okama. While he was once an enemy of Luffy’s as a member of Baroque Works, the two became quick friends, leading Bon Kurei to sacrifice himself for Luffy both at Alabasta and later at Impel Down.
He is currently in Impel Down not as a prisoner but as Okama Queen in level 5.5 .
Luffy would have definitely invited Bon Clay to join the Straw Hats if he didn’t stay behind at Impel Down.
KOBY
Koby was one of the first people Luffy met on his journey. He traveled briefly with Luffy, acting as a temporary navigator after Luffy helped him escape from his servitude to Alvida. Despite being great friends, Koby revealed his dream to become a Marine instead of a pirate, which is why Luffy helped him take that path.
CARROT
Carrot joined the Straw Hat Pirates during the Whole Cake Island Saga and Wano Country Arc. After the Raid on Onigashima, she was appointed by her lords to become the new leader of her people.
Carrot was trained by Pedro, whose will she carries on.
Do you remember what Pedro’s will was in his first chronological in-world debut, in Oden’s flashback? When he was a child he wanted to join the Pirate King’s crew. He asked Roger. And further down the line, back in Whole Cake Island, all he wanted was… to bring the Dawn of the World. He realised only Luffy and the Straw Hats would usher in that new era, the Dawn.
To really fulfill Pedro’s will, the best epilogue would have been Carrot permanently joining the Straw Hat Pirates in Wano.
VIVI & KAROO
Vivi traveled with and assisted the pirates for almost the entire Arabasta Saga and strongly considered joining their crew after Crocodile’s defeat. Though she ultimately declined their offer in favor of working to restore her country, she remains closer to the Straw Hats than anyone else outside of their crew. She and Karoo are now regarded as honorary members of the Straw Hat Pirates, at least by Luffy and the others.
YAMATO
After failing to set sail with Ace, Yamato had been waiting for his brother, Monkey D. Luffy, to arrive at Onigashima. For this reason, Yamato expressed her wish to be freed from Kaido and her intent to leave Wano as one of Luffy’s crewmates as a means to be free and explore the sea like Oden did.
However, Admiral Ryokugyu’s attack on Wano made Yamato realize that others would try the same now that Kaidou was gone and she decided to stay in Wano to help protect it. Luffy agreed and entrusted Yamato to protect Wano for him. Before leaving Wano, Luffy told Yamato that she was free to join his crew at any time in the future and that they would come looking for him when he did.
