Perhaps in this fanfiction, Luffy being a girl secretly could add a new layer to her relationships. For example, her relationship with Zoro might have a different dynamic, with Zoro being even more protective. And it could also change how she is perceived by her enemies. They might underestimate her at first because she's a girl, but then be surprised by her strength.
One interesting idea could be how Luffy's friends react when they find out. Maybe they are shocked at first but then quickly accept it and support Luffy as always.
Perhaps in the fanfiction, Izuku as a girl might have a different relationship dynamic with her friends. Her friendships with male characters could take on a new aspect, like a protective or sisterly role. It could also add a new layer to her relationship with Bakugo, maybe changing the nature of their rivalry to something more complex due to gender differences.
Well, one idea could be that Bilbo's secret as a girl might lead to unique adventures. Maybe she has to hide her identity while on the journey, which could add a whole new layer of intrigue to the story. For example, she might have to pretend to be a male hobbit in situations where being female could be a disadvantage.
One idea could be that Luffy has a secret female identity that only a few crew members suspect. For example, in some fanfictions, Luffy might use this female guise to infiltrate an all - female pirate crew or a secret society where only women are allowed. It adds an interesting twist to the character.
In this type of fanfiction, a great plot idea could be that Naruto's female identity is tied to some sort of ancient prophecy. Only as a girl can she fulfill this prophecy which could involve saving the ninja world in a different way than in the original story. Her secrecy then becomes crucial not just for her own safety but for the fate of the entire world. And as she tries to keep her secret, she has to navigate the challenges of being a girl in a world that expects her to be a boy.
Well, a plot could revolve around Luffy as a girl having to deal with the expectations of femininity in different islands they visit. Some islands might have strict gender roles, and she has to find a way to balance being true to herself as a fearless pirate while also navigating these cultural differences. And perhaps her crew helps her in different ways to overcome these obstacles.
A possible plot for the 'Tsuna is secretly a girl' fanfiction could be that Tsuna is a talented athlete in a boys - only sports team. She has to keep her gender a secret because she's afraid of losing her position. However, as she gets closer to her teammates, she realizes that they would accept her for who she is. Along the way, there could be a rival from another team who discovers her secret and tries to use it against her, but in the end, Tsuna overcomes this obstacle and is able to be open about being a girl.
One idea could be that Ed has to keep her true gender a secret while on her alchemic adventures to avoid discrimination in a male - dominated alchemic world. Another could be that she forms unique relationships with other characters who might suspect or eventually discover her secret.
One idea could be that Percy, as a girl, has to deal with different expectations in the demigod world. For example, some might assume she's not as strong physically, but she proves them wrong by outperforming many male demigods in combat training. Another plot could involve her having a different kind of relationship with Annabeth. Instead of the typical male - female friendship - romance dynamic, they could have a more sisterly bond that still has elements of competitiveness and deep mutual respect.
One idea could be that as a girl secretly, Ed Elric might face different challenges in the male - dominated alchemist world. Maybe she has to hide her true identity while trying to achieve her alchemical goals.
One plot idea could be that Sasuke has been secretly a girl all along but has been hiding it to fit into the male - dominated ninja world. She could struggle with her identity while also having to deal with her feelings for Naruto in a new light. Another idea is that she's a girl in disguise to seek revenge on those who wronged her family, and as the story progresses, her true self starts to emerge.