Nami would probably be shocked at first. She might worry about how this would affect Luffy's journey to become Pirate King. But then she would likely start thinking about practical things like how to take care of the baby on the ship. Sanji would be over the moon, seeing it as an opportunity to cook for a new little life. He might also be a bit jealous that it's Luffy and not him having a baby with Hancock.
One possible plot idea could be that Hancock discovers she is pregnant with Luffy's baby. This could cause a stir in Amazon Lily as they deal with the idea of their empress having a child with an outsider. Meanwhile, Luffy might be oblivious at first, still on his adventures, until the news reaches him and he has to figure out how to be a father while still pursuing his dreams of becoming Pirate King.
Well, it could start with small gestures. For example, Luffy might share his food with Boa Hancock, which is a big deal for him. This simple act could make Boa Hancock see his kindness in a new way. Then, as they interact more, they might have some accidental physical contact like brushing hands. These little things can build up the tension and start to develop their relationship.
One possible plot could be that Hancock discovers she's pregnant after a strange encounter on an island. Luffy, being Luffy, is initially confused but then excited. They could face challenges from the World Government who fear the power of their child. Hancock would use her Kuja abilities to protect their unborn baby while Luffy battles those who oppose them.
Sure. One type of fanfiction could be set in an alternate universe where Hancock and Luffy are forced to work closely together for a common goal, and during this time, Hancock's love deepens. Another could be a story that delves into Hancock's past and how her experiences have led her to fall so deeply for Luffy. And then there are those that simply focus on the cute and endearing moments between them.
One common theme is love and affection. Since Hancock has strong feelings for Luffy, many fanfictions explore how their relationship develops in terms of romantic love.
If they had a baby, Hancock would become more protective not just of Luffy but also of their child. Luffy would have a new sense of responsibility. He might not be as reckless as before, at least when it comes to the safety of his family. Their relationship would deepen as they share the joys and concerns of raising a child in the dangerous world of One Piece.
They could be united by a common enemy that is not related to the main plot of One Piece. Maybe an ancient power or a group of pirates from a far - off land that threatens both the Amazon Lily and the Straw Hats. Working together against this new threat would make their relationship deeper as they rely on each other's strengths. For instance, Hancock's knowledge of the sea around her island and Luffy's fearless combat style would be a great combination.
Well, a very common theme is the power dynamic. Hancock is a powerful pirate queen and Luffy is also a very strong pirate. How they interact in terms of power, whether it's Hancock being in awe of Luffy's fearless nature in the face of power or Luffy not really caring about Hancock's status, is often seen. Also, the theme of friendship and loyalty pops up. Even though Hancock has romantic feelings, there's also a sense of deep loyalty and friendship that is explored in many fanfictions.
Well, there could also be some side characters from both Amazon Lily and the places the Straw Hat Pirates have visited. For example, the Kuja warriors from Amazon Lily could be there to celebrate the marriage. And from Luffy's side, maybe some of the friends they made in different islands like the people from Dressrosa or Alabasta could also make an appearance in the fanfiction to add more flavor to the story.