One common theme is growth. How they've both grown as fighters and as friends over the years. Another is loyalty, showing how they always have each other's backs in different situations.
Friendship is a very common theme. Their long - standing bond from childhood is often explored.
In goku x krillin yaoi fanfiction, a prevalent theme is the journey of self - discovery for both characters. As they enter into this new kind of relationship, they may have to re - evaluate their own identities and feelings. There could also be themes of secrecy and acceptance, especially given the nature of their relationship which might not be as openly accepted in the Dragon Ball universe. Additionally, themes of sacrifice and loyalty that were present in their friendship could be intensified in a romantic context.
There are definitely some out there. However, the quality can vary a great deal. Some might focus on their friendship, while others might explore more of a bromance - type relationship. It really depends on what you're looking for in a fanfic.
The theme of love against all odds is also quite prevalent. Given their different origins and the fact that Goku is already married in the original story, their relationship in fanfics has to overcome many obstacles. This could be social, moral or even physical (like dealing with other powerful characters who oppose their union), but they still find a way to be together, which makes for an interesting read.
Another theme is power transfer or inheritance. Some fanfics might have Bardock passing on some hidden power or knowledge to Goku. This could be related to their Saiyan abilities or some special technique that only their family line can access. There is also the theme of redemption in some cases. If Bardock is brought back in a fanfic, he may seek to atone for his past actions through his relationship with Goku.
One common theme is the discovery of love. Goku, being somewhat naive in matters of the heart, gradually realizes his feelings for Launch. Another theme is adventure. They often go on quests together, which strengthens their bond.
One common theme is rivalry - turned - friendship. Their long - standing rivalry in the original series is often explored in fanfics as a starting point that then evolves into a deeper connection.
One common theme is redemption. Since Broly is often portrayed as a villain initially, many fanfics focus on his journey towards redemption with Goku's help. For example, Goku might show Broly a different way of using his power, leading Broly to change his ways.
Love and family are very common themes. Their relationship is often depicted as a strong bond that withstands Goku's adventures and battles. Chichi is usually shown as the stable presence in Goku's life, and their love story is central.
One common theme is the power of friendship. Despite their differences, Goku and Bulla often form a deep bond in fanfics. Another theme is adventure. They usually go on some kind of exciting journey together, like searching for a powerful artifact or saving the world from a new villain.
One common theme is redemption. Frieza is often portrayed as having a chance at redemption through his interactions with Goku. For example, in some fanfics, Goku's unwavering belief in the good in people (or in Frieza's case, beings) starts to make Frieza question his own evil ways.