Well, they might have a heartfelt conversation about their past experiences. They could talk about the times they were apart and how much they've changed. Since they are meeting again, there could be a lot of catching up to do. They could also plan for future adventures or just enjoy each other's company in a peaceful place like a meadow filled with beautiful flowers.
I'm not sure exactly who they are without more context from the fanfiction itself. They could be two friends, or perhaps two characters from a particular universe like magical creatures or just ordinary beings in a fictional town.
In a Draco and Hermione meet again fanfiction, they might start off with hostility. Draco, having grown up with certain prejudices, could initially be cold. However, over time, they could discover new sides of each other. Maybe they find themselves on the same side in a new magical crisis, forced to work together. As they do, they begin to respect each other's skills and intelligence. Hermione's vast knowledge and Draco's cunning could combine to solve the problem at hand. Eventually, this could lead to a grudging friendship or even something more, as they see past their old Hogwarts rivalries.
They might have a really emotional reunion. Percy could give Annabeth a big, warm hug and they'd start reminiscing about their past adventures together, like the time they were in the Labyrinth or on their quests.
They might go on a new adventure together. Maybe they'll discover a rare Pokémon that neither has seen before and team up to catch it, just like the old days.
They might immediately embrace and share all the adventures they had separately. Gendry could show Arya the new skills he has learned, like advanced blacksmithing techniques. And Arya might tell Gendry about the different places she has been and the people she has met on her journey.
It's also possible that their reunion would be more hesitant. With so much history between them, they might be a bit guarded at first. But as they start to interact more, the old feelings would slowly resurface, leading to a gradual rebuilding of their relationship.
They might have an intense emotional reunion. Edward could be overcome with joy and relief at seeing Bella again. Maybe he'll take her into his arms immediately and they'll just stare into each other's eyes, all the past feelings flooding back.
Well, perhaps in this fanfiction encounter, Rowle has changed. He could approach Hermione with an offer of truce or alliance. Maybe he has seen the error of his ways in the dark wizarding world. Hermione, being the intelligent and cautious witch she is, would be very skeptical at first but might listen to what he has to say.
They might have a warm embrace. Haku could show Chihiro all the new and beautiful parts of the spirit world that have emerged since she left. They could share stories of their time apart, with Haku telling Chihiro about how he has been protecting the spirit world and Chihiro sharing about her life in the human world.
Well, in some fanfictions, when they meet again, Sasuke and Sakura could go on an adventure together. They might face new enemies and in the process, rekindle their relationship. Sasuke could show his protective side for Sakura more than ever, and Sakura would be there to support Sasuke both emotionally and in battle.