On Ash's side, his mom would be extremely happy and would start planning the wedding immediately. She would love Dawn like her own daughter. Ash's other friends like Tracey would send their best wishes. For Dawn's family, they would see Ash as a great match for Dawn. Her mother would be glad that Dawn has found someone who shares her love for Pokemon. Her father would be impressed with Ash's achievements in the Pokemon world and would wholeheartedly approve of the marriage.
Ash's father, if he is introduced in the fanfiction, could be very supportive. He might give Ash some advice on being a good husband. Dawn's family could also be very involved in the wedding preparations. Her grandmother might pass down a family heirloom for Dawn to wear on her wedding day, symbolizing the family's acceptance and celebration of the union with Ash.
Pikachu would be super excited. It has been with Ash for so long and would see Misty as part of the family. It might play more with Misty's water - type Pokémon. Misty's Starmie could be very protective of the new family unit and use its psychic powers to help around the house sometimes.
Jacob's wolf pack would also have a range of responses. Some of the younger wolves might be excited for Jacob, seeing it as a new chapter for their pack. But the older, more traditional wolves might be worried about the implications of this union for the pack's future and their relationship with the vampires. Jacob would have to work hard to convince them that this is a positive step.
Naruto's friends would be very happy for him. They know how much Naruto has longed for a family. His sensei, like Kakashi, would probably give his blessings. Ayame's family would be glad to have Naruto as part of the family. Since Naruto is a hero in Konoha, it would be an honor for them. And the villagers, who have watched Naruto grow up, would also celebrate this union.
Well, their married life could be filled with adventures. They might travel the Pokemon world together, discovering new Pokemon species. Ash's experience in battles and Dawn's knowledge of contests could combine in interesting ways. For example, they could train Pokemon for both battles and contests, creating a unique training regime. And of course, they'd have their own Pokemon family around them, living in a cozy home in a peaceful region of the Pokemon world.
Inuyasha's demon friends and family might be a bit skeptical at first. Some of the more traditional demons might think that a human like Kagome is not a suitable match for Inuyasha. However, over time, they would see how much they love each other and come to accept her. Kagome's family from the future would be worried about her staying in the past but also happy that she has found love. Her mother especially might be sad to see her go but also supportive knowing that Kagome has made her choice.
Sabrina's aunts would probably be overjoyed. They might throw a big celebration in their magical home, inviting all their magical friends. They would see Harvey as a great addition to the family and be happy that Sabrina has found love.
Some of Ash's more competitive Pokémon, like Charizard, might be a bit protective at first. It might see Lillie as someone who could take Ash away from their adventures. But once it realizes how happy Ash is, it would warm up to the idea. Lillie's Pokémon that are more timid, like the Mareanie she has, might be a bit shy around all the new people and Pokémon at the wedding, but still be happy for their trainer.
Ash would probably be very shocked and hurt. Pokemon are like his family, and for Misty to steal one would go against everything he stands for.
Ash might be heartbroken at first. He'd feel a deep sense of loneliness and confusion.