One possible plotline could be that Sasuke discovers some hidden knowledge or power that Kushina had, and he tries to learn from it. Another could be that they are brought together in a time - travel scenario, where they have to work together to fix something in the Naruto world's past.
Well, perhaps a plotline where Kushina, being Naruto's mother, has some sort of unfinished business related to the Uchiha clan that Sasuke gets involved in. They might start off as reluctant allies, but as they spend more time together, they come to understand and respect each other. It could also be a story where they are both haunted by similar nightmares or visions, and they find solace in sharing and trying to overcome them together.
One possible plotline could be a what - if scenario. For example, what if Sarutobi had a closer relationship with Kushina before she met Minato. Maybe they could be friends who gradually develop deeper feelings as they face various challenges in the Hidden Leaf Village together.
One plotline could be that Naruto discovers a hidden power within himself that is linked to Kushina's Uzumaki heritage. This power makes him godlike, and he has to learn to control it while also dealing with the memories and emotions related to Kushina that come with it.
One possible plotline could be that Naruto is influenced by some dark force and turns 'evil'. Kushina, having come back to life somehow, tries to understand what has happened to her son. She then embarks on a journey to find a way to reverse the effects, leading to a series of adventures where they interact in different ways, like Kushina trying to jog Naruto's memories of their family bond.
A more complex plot could involve time - travel or alternate universes. For example, an alternate universe where the universes of Dragon Ball and Naruto are merged. Goku and Kushina meet under these strange circumstances and have to figure out how to deal with the chaos that ensues while also exploring their new - found feelings for each other. This could involve battles against powerful villains who want to take advantage of the merged universes, and Goku and Kushina would be at the forefront of protecting their new world together.
In some fanfictions, their married life could be centered around training the next generation. They could take on students together and teach them the ways of the ninja. This plotline would show how they combine their different fighting styles and philosophies to train the young ones. It would also include their relationship development as they navigate through the challenges of being mentors while being a married couple.
A third type of plot could be a soul - bond story. There's a magical or chakra - based connection between Sasuke and Kushina that they don't understand at first. This connection makes them feel each other's emotions and experiences. As they explore what this means, they grow closer together, sharing secrets and relying on one another in ways they never expected.
The OC could be a wandering ninja who stumbles upon the situation where Kushina is in danger. Maybe they are initially just passing through, but their sense of justice compels them to step in and save her. Then, they might get involved in the larger Naruto world events as a result of this encounter. They could also form a bond with Kushina, which could lead to different relationships with other characters like Minato or Naruto in the future.
A possible plotline could be that Sakura accidentally stumbles upon a hidden memory or dimension where Kushina exists. They then bond over their experiences with the male characters in their lives. For example, Sakura could talk about Sasuke and Kushina about Minato.
One possible plotline could be that Naruto is an orphan found by a different ninja clan. He grows up with different values and skills, and his path crosses with Kushina in a completely non - family - related way. For example, they could meet as rivals in a ninja tournament. Another plotline might involve Naruto being from another village entirely and coming to Konoha on a mission where he teams up with Kushina to fight a common enemy. They then form a bond based on mutual respect and shared experiences rather than a family connection.
Another plotline could involve the Shinigami within Naruto having some sort of mission related to Kushina. The Shinigami might need Naruto to help Kushina fulfill an unfinished task. As Naruto and Kushina work together, they also get to bond on a deeper level, with Naruto learning more about his mother's past and her love for the village and his father.