Obviously, Goku is the most important character. Then his parents, Bardock and Gine. Bardock was a powerful Saiyan warrior, and Gine was a kind - hearted Saiyan. There might also be other characters like Goku's friends on Earth who could be involved in the story in some way, for example, they could be witnesses to the reunion or help Goku's parents adjust to life on Earth.
Well, in the 'Goku reunites with his parents fanfiction', it could start with a sudden appearance of his parents. They might come back through some kind of time - space rift or a special wish on the Dragon Balls. Once reunited, Goku's parents would surely be proud of him. They might help him face a new and powerful enemy that Goku alone couldn't defeat. And there would be a great family dynamic, with hugs and tears all around.
Well, first of all, Naruto would be in shock. But then he would feel an indescribable joy. His father, Minato, could teach him some new and powerful jutsu that only the Fourth Hokage knew. And his mother, Kushina, would probably smother him with hugs and tell him how proud she is of him. They could also help Naruto understand his Uzumaki heritage better.
In a fanfiction, when Percy reunites with his mom, it could be a very emotional moment. Maybe Percy has just come back from a dangerous quest. His mom would probably hug him tightly, tears in her eyes. She might cook his favorite meal right away, and they would sit down and Percy would start telling her all about his adventures.
In this kind of fanfiction, Naruto might first be in shock. He has grown up without his family for so long. He could break down in tears of joy when he sees his father and mother. They would probably embrace tightly. His father might share some of the family's secrets or jutsu with him that were passed down. And Naruto would finally feel complete, having the family love he always longed for.
It might develop by Naruto exploring his family's past through his parents' memories. They could show him places important to the Uzumaki clan that he never knew about. Also, Naruto could introduce his parents to his friends, like Sasuke and Sakura, and there would be some really heart - warming interactions.
I recommend the book "Douluo of Uchiha, Master Ban" to you. The main character of this book is Uchiha Banban. He was ambushed and killed in the Fourth War of Ninja World. After that, he was reborn as his older brother, Naruto Uzumaki's father. In order to prevent the tragedy of Izuna from happening again, he was determined to protect his loved ones and pursue them to become the new Uchiha clan. The author of this book is Guan Zhan. I hope you like this fairy's recommendation. Muah ~š
Maybe in the fanfiction, Harry discovers a magical artifact that has the power to bring back the dead for a short time. When he activates it, his parents appear. They are a bit disoriented at first. His father, James, is amazed at how much Harry has grown and is like him in many ways. Lily, his mother, is just so happy to hold him. They talk about the wizarding world as it is now compared to when they were alive. Harry also shares his experiences at Hogwarts and how he defeated Voldemort, and his parents are filled with pride for their son.
In such a fanfiction, there could be a lot of emotional moments. Maybe they would initially be in shock. They might share stories about their separate lives. For example, Harry could tell his sibling about his adventures at Hogwarts, the friends he made like Ron and Hermione, and the battles he fought against Voldemort. His sibling could in turn share about their own experiences growing up away from Harry. There could also be a sense of instant connection and a feeling of finally having family that truly understands them.