Definitely Toad. Toad has been a loyal friend to both Mario and Peach. He could be the one helping with all the little details of the wedding, like arranging the flowers or setting up the chairs. Yoshi could also be a great addition. He could carry Mario and Peach on their honeymoon as a fun way of transportation. Luigi should be there too, as Mario's brother, he would be an important part of the celebration.
Well, in addition to the obvious ones like Mario, Peach, and Toad, it would be interesting to include some of the less - seen characters. For example, the Boos from the haunted mansions could be invited in a spooky but friendly way. They could add an element of mystery to the wedding. Also, the Chain Chomps could be there as guards, making sure Bowser or any other villains don't crash the party. And of course, the Magikoopas could use their magic to create amazing special effects during the wedding ceremony.
I think Rosalina would be a great character to include. She could come from the stars and bring a special gift for the newlyweds. The Lakitu could be hovering above, taking pictures of the whole event for the Mushroom Kingdom's scrapbook. And then there are the Hammer Bros. They could be part of the entertainment, doing their little hammer - throwing shows during the wedding feast.
Quinn would be an important character to include. Given her past relationship with Puck, her presence at the wedding could add some drama and tension. Santana could also be part of it. She could be the sassy friend who makes sarcastic comments about the wedding but deep down is happy for them. And of course, Mr. Schue. He could give a heartfelt speech at their wedding about how far they've come.
One possible plot could be a grand wedding ceremony. Mario and Peach would invite all their friends from the Mushroom Kingdom, like Toad and Yoshi. They would have a beautiful ceremony in the castle gardens, with Peach in a stunning white dress and Mario in his best suit. After the ceremony, they could go on a honeymoon to a new, magical land that has been discovered in the Mushroom World.
Mario and Peach are the central figures. But often, other characters from the Mario universe play important roles too. Bowser could be a significant character in the fanfiction. He might be jealous of their marriage and try to cause trouble. Toad, as Peach's loyal subject, could also be there, helping with the wedding preparations or being part of their daily life in the castle.
Obviously, Brock should be included. He has been Ash's friend for a long time and could be Ash's best man. He would also add some comical moments to the story, like when he flirts with the female guests at the wedding. Max, May's little brother, would also be a great addition. He could be a bit of a troublemaker at first, not fully understanding why his sister is getting married, but then come around and be really happy for her. And of course, all of Ash's Pokémon, like Pikachu, should be there. Pikachu could even be the ring - bearer in a really cute way.
Obviously, Mario and Peach are the central figures. Mario, with his iconic red cap and overalls, is known for his jumping skills and courage. Peach, on the other hand, is not just a damsel in distress. She can be quite resourceful. In a fanfiction with a lemon aspect, they could be joined by other characters like Luigi, who might be a bit jealous of Mario's lemon - related adventures with Peach. And there could also be some new lemon - loving characters introduced to add more flavor to the story.
Including some new characters like a wedding planner who has some crazy ideas that Troy and Gabriella have to work through. And perhaps a long - lost relative of Gabriella's who shows up and has some interesting family stories to share. This would make the fanfiction more complex and engaging.
The other demigods from Camp Half - Blood should be included. People like Clarisse, who at first might seem grumpy about the whole wedding thing but then has a change of heart and gives a really nice gift. And Nico, who could use his powers to create some amazing lighting effects during the evening reception. Their presence would add a lot of flavor to the story.
The main characters are Mario, Peach, and the lemons play a significant role as well. Mario is the hero who will likely be trying to solve the problems related to Peach being a giantess.
Inuzuka Hana should be in the fanfiction. As Tsume's daughter, she would play a crucial role in the family dynamics. She might have mixed feelings about Naruto becoming her step - father. Also, Jiraiya would be an interesting character to include. His wild and carefree nature could contrast with Tsume's more serious and stoic personality. He could give Naruto some rather unorthodox advice about marriage, which could lead to some comical situations. And Gaara could be added too. His friendship with Naruto could be shown in the context of Naruto's new married life, perhaps with Gaara coming to visit Konoha and interacting with Tsume.
Caroline would be a great character to include. As Elena's best friend, she can offer advice and support to Elena in her married life with Damon. Also, Stefan could be in the story. His relationship with Damon adds depth and complexity. He might be initially hesitant about their marriage but eventually come around to support them.