Well, a very common theme is the reunion in some form. Given that Kushina died when Naruto was born, fanfics often imagine scenarios where they get to meet again, either in a dream - like state or through some sort of time - travel or spirit - related plot device. Additionally, the theme of Kushina protecting Naruto is also quite popular. It could be in the form of her spirit looking out for him during difficult times in his life. And then there's the theme of Naruto learning about his family's past from Kushina, which helps him understand his place in the ninja world better.
One popular theme is family heritage. Since Kushina is Naruto's mother, many fanfics explore how Naruto discovers and embraces his Uzumaki heritage through his connection with her. Another theme is mother - son bond. Writers often delve into the deep emotional connection that Naruto could have had with Kushina if she had been alive. Also, the theme of Kushina's influence on Naruto's ninja path is common, like how her skills or her spirit might have guided Naruto in his battles and growth as a ninja.
The theme of family and legacy is very prominent. Fanfics may explore how Kushina's love and her story became a part of Naruto's own journey. It could also be about how Naruto discovers more about his mother as he grows, and how that knowledge shapes his actions and decisions. Some fanfics also touch on the idea of Kushina's friends and how they might have interacted with Naruto if they had known about his relation to her.
Well, her connection to the Hidden Leaf Village is a common theme. How she fit into the village, her friendships and rivalries there. Some fanfics also focus on her as a kunoichi. They might show her on missions, her combat skills, and how she was respected among her comrades. And of course, the theme of her legacy, especially in relation to Naruto. How her sacrifice and her love for her son became a driving force in Naruto's life.
Another theme is redemption. Some fanfics have Kushina making up for the time she lost with Naruto. She tries to correct the mistakes that happened in Naruto's life because of her absence. For example, she might help him deal with the villagers' hatred in a different way.
There are many Naruto fanfics that focus on different aspects of the Naruto universe. Some popular ones might involve adventures of Naruto and his friends, or the backstories of characters like Kushina. For example, there could be fanfics about Kushina's life in Uzushio before coming to Konoha. Another type could be about Naruto's training and how he overcomes challenges inspired by his mother's spirit.
Another reason is the emotional depth. Kushina was a powerful and loving character. Writing fanfics about her and Naruto allows for a lot of emotional storytelling. There can be so many different ways to show their love for each other, from her protecting him in new ways to her teaching him things that he missed out on. It's a way for fans to explore different emotional landscapes within the Naruto world.
One common theme is family. Since Kushina is Naruto's mother, many fanfics explore their mother - son relationship in more depth. Another theme could be the backstory of Kushina in the Uzumaki clan. Some fanfics also focus on how Kushina's personality traits are passed on to Naruto.
There are stories that focus on the emotional healing aspect. Given Naruto's tough childhood without his parents, some fanfictions show how Kushina's presence (even in a spiritual or time - travel way) helps Naruto heal his emotional wounds. Additionally, the theme of passing on knowledge from Kushina to Naruto, like unique sealing techniques, is also quite common in these fanfictions.
One interesting theme could be her relationship with the Uzumaki clan. Since she was an Uzumaki, fanfics might explore the clan's secrets and how they related to her. Another theme could be her role in the Fourth Great Ninja War in alternate universes.
One popular theme is friendship. Despite their differences, Naruto, Sakura, and Sasuke have a strong bond that many fanfics explore. Another theme is redemption, especially with Sasuke's character arc. His journey from being an avenger to finding his place among his friends again is often written about.
One popular theme is exploring their relationship in an alternate universe. For example, a universe where Kushina didn't die and got to raise Naruto. It often delves into how their mother - son relationship would be different and how it would impact Naruto's growth and the Naruto - verse as a whole.