There could also be a fanfiction about how Kushina and Minato supported each other during difficult times in the Hidden Leaf Village. Maybe during a war or a crisis, they stood by each other, with Kushina using her sealing skills and Minato his speed to protect the village and each other. This would highlight their loyalty and love for each other and the village.
One appropriate theme could be their friendship and how they supported each other in the ninja world. For example, Minato's leadership and how Kushina and Mikoto were part of his support system.
Love is a very common theme. Their relationship, from falling in love to building a family, is often explored. For example, in many fanfictions, their first meeting and the gradual development of their feelings are depicted in great detail.
One common theme is the idea of sacrifice. In many fanfictions, either Minato or Kushina is willing to sacrifice themselves for the other. It shows the depth of their love. Another theme is the power of their bond. Their relationship is often depicted as something that gives them strength, whether it's in battle or in dealing with the politics of the Hidden Leaf Village.
One of the most popular themes is their love story. People love to read about how they met, courted, and got married. Another theme is their roles as parents. Since they are Naruto's parents, fanfictions often explore how they would have raised Naruto if they had survived. For example, some fanfictions show Minato teaching Naruto his signature jutsu at an early age.
One common theme is sacrifice. Since they are ninjas, they often have to sacrifice their personal time together for the sake of the village. For example, Minato may have to go on dangerous missions, leaving Kushina worried but still supporting him.
One common theme could be rewriting the Naruto story with different character development for Minato and Kushina. Maybe they are portrayed as more flawed or making different choices that lead to alternative storylines.
I'm not sure specifically as I haven't read this particular fanfiction. But it might be a very dark and disturbing take on the relationship between Minato and Kushina in a fictional, non - canon story created by fans. It could involve the author exploring a negative and inappropriate version of their interactions.
Well, in some fanfictions, the moment when Minato sacrifices himself to save the village while Kushina is already dead is extremely emotional. It shows his selflessness and also the love he has for the village and his family. Also, the flashbacks in some stories about their early days together, like when they trained together as young ninjas and slowly fell in love, are really sweet and emotional.
On a more personal level, they could face internal guilt. As Naruto grows up and achieves great things on his own despite their neglect, Minato and Kushina may realize what they've missed out on. This realization could cause them a great deal of internal turmoil and regret for not being there for their son when he needed them.
One common theme is isolation. Naruto would be all alone without his parents, and this would shape his relationships. Another theme is revenge. In some fanfictions, he might seek revenge on the village for his abandonment.