In some fanfictions, a crossover like this could lead to a romantic relationship between Naruto and Nezuko. However, this would be a very different kind of relationship as they come from such distinct backgrounds. Their relationship could be a slow - burn one, starting from mutual respect and growing into love as they face various challenges together.
Yes, there are some. You can check fanfiction websites like Archive of Our Own. Just search for 'naruto x nezuko' in their search bar, and you'll likely find a variety of stories written by different authors with different takes on this crossover.
One common theme is the clash of their different worlds. Naruto's ninja world and Nezuko's demon - slaying world can create interesting scenarios. Another could be the idea of them protecting each other despite their differences.
Another interesting part is the character interaction. Naruto is a very energetic and determined character, while Nezuko is more of a silent but strong presence. Their different personalities can lead to some really unique and engaging dialogues and moments in the fanfic. For example, Naruto might be all about charging into a fight, while Nezuko's more calculated approach could either clash or complement his style, making for great reading.
Another option is Wattpad. There are many Naruto and Nezuko fanfictions on there as well. Some of the stories on Wattpad are more focused on the emotional and relationship aspects between the two characters, while others might be more action - oriented. You can explore different genres and writing styles on this platform.
A really cool Naruto and Nezuko fanfic is 'When Naruto Meets Nezuko'. This story starts with Naruto being transported to the Demon Slayer world. He quickly meets Nezuko and they start an adventure to find a way to send Naruto back home while also helping Nezuko in her fight against demons. The fanfic has great character development and some really exciting action scenes.