Another plot could involve a Pokémon contest where May is a contestant and Ash is there to support her. But something goes wrong with the contest rules due to a villain's interference. Ash and May then team up to expose the villain and make sure the contest is fair for all the contestants. It could also be a chance for their relationship to grow deeper as they face challenges together.
Another interesting plot could be a time - travel story where Ash and Cynthia are sent back in time to the early days of the Pokémon world. They have to adapt to the different rules and ways of training Pokémon back then while also trying to find a way back to their own time.
One plot idea could be that Ash is captured by a new and powerful villain who wants to use his Pokémon knowledge for evil. Another could be that he's captured by a group who mistake him for someone else and he has to prove his identity while trying to escape. Maybe he's captured by an ancient Pokémon that has some sort of grudge against trainers and he has to convince it that not all trainers are bad.
Another plot could be that the reader is from a different dimension where Pokémon don't exist in the same way. When they end up in Ash's world, Ash helps them understand and adapt. Along the way, they develop a deep friendship as the reader discovers the joys and challenges of the Pokémon world. It's a unique take on their relationship that doesn't involve any adult themes.
One idea could be Ash encountering a Legendary Pokemon that has lost its memory. Ash then tries to help it regain its memories while protecting it from poachers. Another could be a time - travel plot where Ash is sent back in time and has to team up with a Legendary Pokemon to prevent a great disaster from happening in the past that would change the future of the Pokemon world.
Another plot could be set in a world where a strange phenomenon is affecting Pokémon. Ash and Cynthia join forces to investigate. Along the way, they discover a new type of Pokémon evolution that has been hidden for centuries. As they work together, they start to develop a deep friendship that might turn into something more.
Well, perhaps May decides to pursue her own Pokémon journey alone, leaving Ash behind. This could break Ash's heart as he might have developed deep feelings for her during their adventures together. Maybe she meets a new trainer who she seems more interested in, and Ash feels replaced.
One idea could be that Ash and May are in a Pokémon competition held in a special, romantic location. After May wins, Ash impulsively scoops her up bridal - style in celebration. This could lead to a moment of realization between them about their deeper feelings for each other. It could be a really cute start to a fanfiction.
Perhaps Ash gets a special ability from a Legendary Pokémon, like the ability to communicate telepathically with all Pokémon. This causes him to be hunted by an organization that wants to use this power for their own gain. With the help of various Legendary Pokémon that he befriends on his journey, Ash has to protect himself and his new power.
A really interesting plot might be that Ash is chosen by an ancient dragon deity to be its champion. As a Dragon Master, he has to go on a quest to collect special dragon orbs scattered across different regions. Each orb gives him new powers or abilities related to dragon Pokémon. Along the journey, he faces challenges from other trainers who also want the orbs for their own purposes.
One possible plot could be that Ash discovers a new and extremely powerful Pokémon that gives him an edge in battles. Misty is initially in awe of his newfound strength. They then embark on a journey together through a mysterious forest where they face various challenges and their relationship deepens as they rely on each other. Eventually, they become closer friends and Ash uses his new power to protect Misty from a group of wild and dangerous Pokémon.