One idea could be that a group of former classmates reunite after many years and discover that one of them has become a famous singer. They then relive old memories while also getting to know the new and successful side of their friend.
Perhaps a time - travel themed Twilight Reunion Fanfic. A character accidentally travels back in time to key moments in the Twilight series and has to figure out how to get back to their own time without changing the course of events too much. This could lead to some interesting reunions with characters at different points in their lives, like seeing a younger Carlisle or a pre - transformation Jacob.
Another interesting concept is a reunion that is centered around a magical tournament. The characters are invited back to Hogwarts to participate or watch. Old rivalries might be reignited in a friendly way, and new friendships could form among the younger generations as they look up to the famous Harry Potter and his friends.
One idea could be that Goku has been away on a long and difficult training journey. The reader, who is an old friend, hears of his return and goes to meet him. They then share stories of their adventures since they last saw each other, and Goku shows off some of his new techniques.
One of my friends went to his high school reunion. There was a guy who used to be really shy in school but showed up at the reunion as a confident and successful entrepreneur. He told amazing stories about his business adventures around the world. Another story is about two classmates who had a huge fight in high school but at the reunion, they hugged and forgave each other, realizing how silly their feud was back then.
Perhaps in the fanfic, one of the members has become a successful solo artist but is feeling a bit lost and lonely. The reunion is proposed as a way to regain that sense of purpose and connection. They all come together, and during the process, they share their individual experiences since the group disbanded. This leads to a deeper understanding among them and a new start for the group, not just in terms of performing but also in their personal relationships.
One idea could be exploring the backstory of an S - class missing - nin. Maybe they had a noble reason to turn their back on the village at first, like trying to protect a loved one from a corrupt system within the village.
A great plot could involve a Pokemon reunion where the Pokemon themselves organize the event without the trainers knowing. They set up all kinds of challenges and games for each other, and the trainers are left wondering what their Pokemon are up to. It could also be about a group of retired trainers who reunite and share stories of their adventures, and their Pokemon also have a sort of 'reunion' among themselves, showing off new skills they've learned over the years.
One idea could be that the original Glee club members reunite to put on a charity show. They face old rivalries resurfacing but also rediscover their love for performing together. Maybe some of them have become big stars and some are still struggling, and they learn from each other's experiences.
There was a class reunion horror story where a person thought they had made a great life for themselves, but at the reunion, everyone was showing off their amazing careers and luxurious lifestyles. This person felt so inferior and out of place. It was like all their insecurities came rushing back. They expected a friendly get - together but instead it turned into a competition that made them feel terrible.
One positive experience is seeing old friends again. For example, two friends who had a small misunderstanding in school got to talk it out at the reunion and became good friends once more.