Sure, there probably is. Fanfiction thrives on creativity and exploring different relationships and scenarios. A story about Vampire Naruto and Kushina falling in love could be a very creative and engaging piece. Some fanfiction writers like to blend different genres or concepts, like vampires into the Naruto world. So, it's very possible that such a fanfiction exists. You could try using specific search terms on fanfiction platforms to locate it.
Many fanfictions explore Naruto's discovery of his mother Kushina's love. Since he grew up without her, when he finally learns about her through memories or other means in fanfictions, it creates a deep emotional impact. The love can be shown as something that gives Naruto more strength and purpose. For example, in some stories, he realizes how much she sacrificed for him and it makes him even more determined to protect the village she loved.
In a fanfiction, Naruto discovers old letters from Kushina that were hidden away. As he reads them, he gets to know a more personal side of his mother and feels an even stronger bond of love towards her. It's a story of connection through words and memories.
In a fanfiction, perhaps Kushina was able to leave a part of her chakra within Naruto when she died. This chakra has memories and emotions of her love for him. As Naruto gets stronger and faces difficult battles, this chakra activates and gives him not only power but also the feeling of his mother's love, which heals his emotional wounds and gives him the motivation to keep fighting.
Another aspect could be that the fanfiction delves into how Kushina's presence affects Naruto's relationships with others. For instance, his relationship with Sasuke could be different. With a strong maternal figure in his life, Naruto might be more stable emotionally and be able to approach Sasuke in a more understanding way, which could potentially change the whole dynamic of their rivalry and friendship.
Yes, there are quite a few. You can start by looking on fanfiction websites like FanFiction.net or Archive of Our Own. Some of these fanfictions might explore a different kind of relationship between Kushina and Naruto, like what could have been if Kushina had survived. They often delve into the emotional bond that could have developed between mother and son in a more complex way, with added elements of love and care that go beyond the normal mother - son relationship shown in the original series.
One theme could be sacrifice. Kushina sacrificed herself for Naruto, and a fanfiction could explore how Naruto honors that sacrifice through his love for her. It could also be about legacy, as Naruto carries on Kushina's will.
One heartwarming moment could be when Kushina first realizes her feelings for Naruto. Maybe it's during a training session where Naruto shows his determination and Kushina sees the man he's becoming. It's a moment of realization and the start of a deeper connection.
A fanfic might depict a dream sequence where Naruto travels back in time and meets Kushina as a young girl. He is initially confused but soon realizes where he is. Kushina, being the curious girl she was, befriends Naruto right away. They start training together, and Naruto imparts some of his future knowledge in a very veiled way. Kushina starts to develop feelings for this strange but kind boy. As the dream nears its end, Naruto tells Kushina that she will have a great future and a son who will change the world. When Naruto wakes up, he feels a new sense of connection to his mother and is even more motivated to live up to her expectations.
In some fanfictions, the authors might take creative liberties and create alternate universes where Naruto and Kushina interact in different scenarios. For example, they could be on a joint mission together, and through that, we see their personalities shine. Kushina's fiery nature and Naruto's determination would make for an interesting dynamic.