One idea could be that the OC is a time - traveler who accidentally lands in Caulifla's universe. The OC has unique powers that Caulifla is intrigued by, and they start training together. This could lead to a friendship that slowly turns into something more as they face various challenges together in the tough Saiyan - filled world.
Perhaps the OC is a healer from a different planet. Caulifla gets seriously injured during a battle, and the OC comes to her rescue. As Caulifla recovers, she discovers the OC's gentle nature which is a contrast to her own warrior - like personality. They bond over their differences and start a relationship that defies the norms of their respective cultures.
One idea could be Caulifla traveling through time. She could end up in the past during the Saiyan - Vegeta wars and have to decide whether to interfere or not. Another could be Caulifla getting trapped in a magical realm where she has to fight strange creatures with unique powers to find her way out. Maybe she could also form an alliance with an unexpected character, like a villain who has a change of heart.
Well, perhaps the OC is a master of a rare form of martial arts. Caulifla, being the battle - hungry Saiyan - like character she is, challenges the OC. During the fight, the OC shows not only great combat skills but also a sense of honor and justice. This catches Caulifla's attention. Later, they find themselves on the same side against a common enemy and their relationship blossoms from there. They could also have cultural exchanges, as the OC might come from a very different culture within the One Piece universe.
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.
Perhaps an OC is a young archaeology student who idolizes Nathan Drake. They manage to get involved in one of his expeditions through sheer determination. Along the way, they learn from Drake and also teach him new things about modern archaeological research methods. It could be a story of growth and adventure for both characters.
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.
Maybe in the fanfiction, they discover a new threat to the universe together. Caulifla's determination and Gohan's intelligence would be crucial in figuring out how to defeat this new enemy. They could start off as rivals, not trusting each other at first, but as they face the challenges, they grow to respect and eventually fall in love with each other.
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.
One idea could be an OC who is a lightning - style user in Kumogakure and has to face a powerful enemy from another village. The OC could discover a new jutsu during the battle.
A story about an OC who is a healer in the Injustice 2 world could be really engaging. In a world full of battles and destruction, this OC could be trying to heal not only the physical wounds but also the emotional and psychological damage that the characters have endured. They might face challenges like being kidnapped by villains who want to use their healing powers for their own evil purposes.