In the Dragon Ball universe, there are many strange and wonderful things. King Kai might have access to some rare or magical items. He could use one of these items to help Goku's tail grow back. For example, there could be a special fruit on his planet that has regenerative properties. When Goku consumes it or King Kai uses it in some other way, it triggers the growth of the tail.
It could also be a symbol of a new power - up. In the Dragon Ball series, new physical changes often lead to increased power. So, getting his tail back might mean that Goku is about to reach a new level of strength. Maybe he'll be able to transform into a new form that is related to his Saiyan heritage and the presence of the tail. This could give him an edge in future battles against stronger opponents.
We can conclude that Xu Kai is a person who cares about the elderly very much. He often returns to the countryside to take photos and give gifts to the elderly. His actions made the old people feel warm and companionable. In addition, there was also some information about Xu Kai's participation in variety shows and activities, but there was no mention of his return home. Therefore, we can't get a definite answer to the question of Xu Kai going home.
Adventure is another typical theme. They could go on adventures together, either in the Other World or on Earth. These adventures can range from fighting new villains to exploring uncharted territories. This theme allows for a lot of action and excitement in the fanfictions.
One could expect an exciting adventure. Maybe it'll involve Goku's power being used in a unique way to protect the timeline that Supreme Kai of Time oversees. It could also show a different side of their relationship, perhaps a friendship that develops as they face challenges together.
Another storyline could involve Supreme Kai of Time getting into trouble in a different timeline and Goku having to rescue her. Along the way, they discover new forms of power and new allies.
At present, there was no conclusive evidence that Wang Kai and Tan Songyun's relationship in real life was beyond the scope of professional partners and friends. Although their performances in plays and interactions in life showed good work ethics and friendship, they did not publicly disclose the latest news about their relationship. When Tan Songyun answered the question about whether it was possible for her to be with Wang Kai, she said," It depends on fate." This reflected her views on relationships and her respect for possible relationships in the future. Therefore, there was no clear answer to the question of whether Wang Kai and Tan Songyun had a special relationship in real life.