One common theme could be the exploration of their symbiotic relationship. Given that Kushina was the host of the Kyuubi, stories might delve into how they interacted on a mental or emotional level. Another theme might be the power dynamics, as the Kyuubi is an extremely powerful entity and Kushina had to control it. Also, stories may focus on their backstories and how their relationship might have been different if certain events in the Naruto universe hadn't occurred.
Common themes may include the power dynamics between Kyuubi and Kushina. Since Kyuubi is a powerful entity and Kushina was its host, fanfiction might play with this idea in various ways. In some lemon fanfiction, there could be themes of forbidden love or a complex relationship that goes beyond the normal host - tailed beast relationship. But again, due to the 'lemon' nature, these stories can be quite adult - oriented and not for everyone.
A sense of discovery is also a common theme. Both characters might be discovering new aspects of themselves and their feelings for each other. It could involve the discovery of a new form of love that they hadn't experienced before. This theme can add an element of excitement and novelty to the fanfiction, as readers get to follow along with the characters' emotional and self - discovery journeys.
One common theme is family. Since Kushina is Naruto's mother, fanfictions often explore the family bonds. They might show how Naruto's connection to Kushina affects his relationship with the Kyuubi. Another theme is power. The Kyuubi's power within Naruto is a huge aspect. Fanfictions may deal with how Naruto learns to control it, and how Kushina's own experiences with the Kyuubi's power can help or hinder Naruto. Redemption can also be a theme. The Kyuubi, which was once seen as a monster, could be redeemed through its relationship with Naruto and the influence of Kushina's memory.
In kyuubi x oc fanfiction, a prevalent theme is the struggle between good and evil. The Kyuubi can be seen as a force that can be used for good or evil, and the OC often plays a role in influencing this. Another theme is redemption. If the Kyuubi has a dark past, the OC can be part of its redemption story. Identity is also a common theme. The OC may struggle with their own identity in relation to the Kyuubi, and the Kyuubi may also have an evolving identity as it interacts with the OC. Additionally, the theme of loyalty is often explored, as both the OC and the Kyuubi have to decide how loyal they are to each other in different situations.
One common theme is the power struggle. Since Kyuubi is a powerful force and Naruko is its host, there's often a struggle for control and dominance in the relationship which makes for an interesting dynamic.
There may be. Fanfiction is a vast world, and the Naruto fandom is quite large. Since Kushina has a connection to the Kyuubi in the Naruto series, it's possible that fans have explored their relationship in fictional stories. However, the availability might depend on how popular this particular pairing is among the fanfic writers. Some pairings are more common and thus have more stories written about them, but it's still worth looking for.
The theme of mentorship or friendship - turned - love is also seen. Maybe Kakashi starts as a mentor to Kushina, or they begin as friends and then feelings develop over time. Another aspect could be the exploration of their pasts. Both characters have had difficult experiences in their lives. Fanfictions might explore how these pasts shape their relationship, like how Kakashi's experiences with his team and Sensei could influence his relationship with Kushina, and how Kushina's upbringing as a Jinchuriki affects her feelings towards Kakashi.
One common theme is family. Since they are mother and daughter, stories often focus on how they build or strengthen their family bond. Another theme is legacy. Kushina's legacy and how Naruko lives up to it or carves her own path while still being influenced by her mother.
A less common but interesting theme could be cultural exchange. Kushina has her own cultural background as an Uzumaki, and Hinata has the Hyuga clan's traditions. Fanfictions could explore how they share and learn from each other's cultures, which would add a unique dimension to their relationship in the fictional stories.
One common theme is family. Since Kushina is Naruto's mother, many fanfictions focus on them building a relationship that they were deprived of in the original story. It's about filling that void of a mother - son bond.