A plot could involve Caulifla being from a parallel universe where she is the only survivor of her race. Goku meets her during a multiverse tournament and decides to help her. As they train and fight side by side, they develop a deep bond that goes beyond friendship and they explore their new relationship while facing various challenges from other universes.
One interesting plot idea could be Goku training Caulifla in a new form of Ultra Instinct. This would allow for a deep exploration of their mentor - mentee relationship. Caulifla is already a strong fighter, but with Goku's guidance, she could reach new heights. Another plot could involve them teaming up against a powerful new enemy that neither could defeat alone. They'd have to combine their unique fighting styles and powers to win.
Maybe a fanfiction where Caulifla develops feelings for Goku during their training sessions. However, Goku, being oblivious as he often is, doesn't notice at first. Caulifla tries to prove herself to Goku by constantly challenging stronger opponents. Their relationship could be a mix of friendship and the start of something more, with a lot of action-packed scenes in between.
A plot could be Cabba confessing his feelings to Caulifla. He might be nervous at first, but after a big battle where they protect each other, he finds the courage. This would create a new dynamic in their relationship.
Perhaps a story where Caulifla and Goku are on a mission together in an unknown planet. They face various challenges and have to rely on each other's strengths. Caulifla might initially be overconfident, but Goku's experience helps her to understand the importance of strategy and teamwork. Along the way, they start to respect each other more deeply.
Caulifla and Goku's relationship in fanfiction could be really interesting. Maybe in this fanfiction, they start as rivals. Caulifla, with her Saiyan pride, wants to prove she's stronger than Goku. But as they fight more, they begin to understand each other's fighting styles and develop a mutual respect. This could lead to some really cool training sessions where they both learn new techniques from one another.
One idea could be a time - travel fanfic where Bulma accidentally sends Goku back in time to a period before they met. Goku has to figure out how to get back while also dealing with the differences in that time period. Another could be a story where Bulma creates a new device that gives Goku a new power - up, and they have to test it out against a new, powerful enemy. A third idea is a fanfic set in an alternate universe where Goku and Bulma are the rulers of Earth and have to deal with diplomatic issues with other planets.
Their powers could combine in a fusion. Just like how Goku has fused with Vegeta in the past, he could potentially fuse with Caulifla. This would create a new and extremely powerful warrior. Their combined Saiyan powers along with their unique fighting styles would make for an unbeatable force.
Definitely Vegeta. His rivalry with Goku and his own Saiyan pride would add an interesting dynamic, especially when Caulifla is involved. He might be initially skeptical of their relationship and could even challenge Caulifla to prove herself worthy of Goku's attention.
One idea could be that Female Vegeta and Goku are forced to team up for a special mission. They start off bickering as they usually do, but as they face challenges together, they begin to respect each other's fighting styles more. Maybe they have to battle a new, extremely powerful enemy that neither could defeat alone. This situation could lead to some interesting character development and a budding friendship or something more.
A plot could involve Bulma creating a new device that Goku needs to use in order to defeat an extremely powerful enemy. Goku has to learn how to operate this device with Bulma's guidance, and they face many obstacles along the way. This would show their cooperation and how their different skillsets complement each other. It could also lead to some comical moments as Goku tries to understand the complex technology. Another interesting plot could be that they are both transported to an alternate dimension where the rules of the Dragon Ball world are slightly different. They have to figure out how to adapt and find a way back home while also uncovering the secrets of this new dimension.