Common themes include the father - son relationship. This is explored in different ways like Goku's absence at times and how it affects Gohan and then how they reconnect. Another is the exploration of Gohan's potential. Goku is usually there to unlock that potential. There are also themes related to the Saiyan culture. How Goku passes on knowledge about their race to Gohan and how Gohan uses that knowledge in battles and in life.
One common theme is the exploration of a forbidden or unexpected love. Since their relationship in the original series is father - son like, in the fanfic it's a complete twist. Another theme could be the power dynamics, as both Goku and Gohan have different levels of power.
A common theme is the growth of Gohan. Goku often plays a crucial role in this, whether it's through training or just being a role model. For example, in many fanfictions, Goku's unwavering determination inspires Gohan to become stronger.
One common theme is the strengthening of their family bond. Goku might show his love through training Gohan more intensively.
One common theme is the growth of their relationship. It often shows how Gohan looks up to Goku and how Goku mentors Gohan. Another theme is power - up. They usually train together to reach new levels of power to face various threats.
Since yaoi often involves romantic and emotional aspects, in goku x gohan yaoi fanfiction, themes like hidden love, forbidden feelings could be common. Goku being a father - figure to Gohan in the original series makes it a rather unconventional pairing, so the theme of breaking taboos might also be present.
One common theme is the growth of Gohan. Goku often plays a role in pushing Gohan to reach new heights in his power and self - discovery.
In a Gohan x Goku fanfic, their relationship can be delved into by creating scenarios where they have to rely on each other completely. For example, if they are in a situation where Goku's strength and Gohan's intelligence are both required to escape. Their different personalities can also be highlighted. Goku's carefree nature contrasted with Gohan's more studious and responsible side. And of course, flashbacks to Gohan's childhood and how Goku's presence or absence affected him can add depth to their relationship.
Another theme is adventure. The female characters usually join Gohan in his adventures, whether it's fighting new villains or exploring new parts of the Dragon Ball universe. This adds an extra dimension to the story and creates new storylines.
One common theme is knowledge and discovery. Since he is a professor, many fanfics revolve around his search for new knowledge or his sharing of knowledge with others.
Power and training. Since Goku is known for his power - seeking, his brother in fanfics often has a similar drive. They might train in unique ways or discover new forms of power.