Rebecca could potentially be in Luffy's harem. After Luffy helped her in Dressrosa, she might develop feelings for him. She is a strong - willed and kind - hearted character. Another could be Shirahoshi. Luffy has a special connection with her as he saved her from being captured. Her gentle and innocent nature would contrast with some of the other more assertive members of the harem.
One popular one could be 'Luffy's Unusual Crew Additions' in which different female characters from the One Piece world form a unique bond with Luffy in a harem - like scenario. It has interesting character interactions.
Zoro could be one. His loyalty to Luffy could potentially turn into something more in a harem - themed fanfiction. Sanji might also be in her harem, given his chivalrous nature towards women and his deep respect for Luffy. Usopp could be another, as he looks up to Luffy and in this context, that admiration could develop into romantic feelings. And perhaps some new characters introduced specifically for the fanfiction, like a mysterious and handsome pirate from a far - off land who is drawn to Female Luffy's unique aura.
You could also try searching on Tumblr. There are many One Piece fans on Tumblr who create and share fanfiction. By using the appropriate tags like #luffy x harem #OnePieceFanfiction, you can discover some interesting works. However, be aware that Tumblr's search can be a bit finicky sometimes, so you might need to dig a little deeper.
One possible storyline could be Luffy and his harem going on adventures together on different islands. They face various challenges, and during their journey, they develop deeper emotional bonds with Luffy. For example, they might help him fight against powerful pirates or discover hidden treasures. Along the way, their relationships grow and there are many heartwarming and exciting moments.
One popular storyline could be Female Luffy traveling to different islands and unknowingly attracting various characters into her harem. For example, she might rescue a prince from a dangerous situation on an island, and he becomes smitten with her. Another could be where her unique personality and leadership in the Straw Hat crew make some of her male crewmates develop deeper feelings for her in a more romantic sense. Also, there could be a plot where Female Luffy has to deal with rivalries among those in her harem while still striving towards the One Piece.
The theme of acceptance is quite common. Fem Luffy often has to be accepted by the other characters in the story. This could be because she's different due to her gender or her slightly different personality traits. Also, the theme of self - discovery is prevalent. As fem Luffy navigates the pirate world, she discovers more about herself, her abilities, and her place in the grand scheme of things.
One popular luffy and fem luffy fanfiction is 'Fem Luffy's Adventure'. It shows a different side of Luffy if she was a female, with unique storylines and character developments. Another one could be 'Fem Luffy in a New World' which explores how fem Luffy might interact with the other characters in the One Piece world in new and interesting ways.
Some fanfictions also pair Luffy with Hancock. Given Hancock's infatuation with Luffy in the original series, it's not a stretch to develop a full - blown love story. Her powerful status as a pirate empress and Luffy's carefree nature can create an interesting dynamic, with Hancock trying to win Luffy's heart while he is mostly oblivious to her romantic intentions.