It's difficult to say exactly what the plotlines would be as it's such an unusual concept for Pokemon fanfiction. But it could be that some sort of time - travel or dimension - hopping event leads to a world where different biological rules apply to Ash and Gary, resulting in pregnancy. It could also be a story about them having to deal with the social and personal implications of such an unexpected situation within the Pokemon world.
Maybe a plotline could involve a powerful Pokemon's ability that has unexpected consequences and results in Ash or Gary becoming pregnant. Or perhaps it could be part of a very elaborate and strange fan - created prophecy that they must fulfill by experiencing this situation. However, these types of plotlines are not typical in the Pokemon fanfiction genre and are more on the extreme and creative side.
One possible plotline could be that it's set in an alternate universe where some magic or strange phenomenon causes them to become pregnant. Another could be a scientific experiment gone wrong scenario. But these are just wild speculations as such a concept is very far - fetched from the original Pokemon concept.
I'm not sure if there is specifically an 'appropriate' one. Fanfiction can vary greatly in nature and content. You could try looking on well - known fanfiction websites like FanFiction.net or Archive of Our Own and search for it while filtering through the results to find something that adheres to your idea of appropriate.
One possible theme is the transformation of a rivalry into something deeper. Gary and Ash were rivals, but in this fanfiction, it could be about how that rivalry can turn into love or a very strong friendship. Another theme might be self - discovery. Gary might be on a journey of realizing his true feelings for Ash.
Maybe Harrison comes to Ash's town and challenges him. Ash accepts, and during the battle, there are flashbacks of their past experiences and how they got to where they are as trainers. This could add depth to the story and show their growth.
One possible plotline is that Ash is on a journey to prove himself against the toughest opponents and finally faces Brandon. He uses his Pikachu in a unique way to gain an edge in the battle.
A plotline could involve a curse or a strange experiment gone wrong that causes Ash to be in a situation where he has to give birth. Or perhaps there's a parallel universe where the rules of Pokemon are different and male characters can give birth. Ash could be on a journey in this universe and have to deal with this new and unexpected situation, learning about himself and the world around him in a completely different way.
One plotline could be that Ash uses his ability to speak to Pokemon to solve a mystery. For instance, a group of Pokemon are acting strangely, and by talking to them, he discovers that there is a hidden force affecting them. Another could be that he has to convince a powerful and angry Pokemon not to destroy a village by communicating with it on a deeper level.
In this fanfiction, Ash and Gary's rivalry is often intensified. Ash is usually portrayed as the determined and passionate trainer, while Gary is the more arrogant yet highly skilled counterpart. Their battles in the fanfic can be epic, with both using their unique Pokémon strategies.
In Pokemon fanfiction, Ash and Gary's relationship can be seen as a complex one. They start as rivals, constantly competing with each other. However, this rivalry can be seen as a form of love in a sense. They push each other to become better trainers. Gary's initial arrogance and Ash's determination create a dynamic where they are always aware of each other. In some fanfictions, this evolves into a deep respect and a kind of friendship - love that goes beyond just the typical rival - rival relationship.
Well, in this kind of fanfiction, it often explores a different side of the relationship between Gary and Ash. Maybe it shows Gary having some newfound feelings for Ash that he decides to confess. It could be an interesting take on their characters as in the original Pokemon series, they were more like rivals.
One popular plotline is a friendly rivalry turned into a partnership. Ash and Gary, who have been competing for so long, realize they can achieve more together. They might team up to face a powerful new threat in the Pokemon world, like a mysterious and extremely strong Legendary Pokemon that is causing chaos. Another plotline could be a journey of self - discovery for both of them. They travel together and learn from each other's different training styles, which helps them to grow not only as Pokemon trainers but also as individuals. There are also fanfics where they might have to overcome a misunderstanding or an old grudge between their families that has been affecting their relationship all along.