Naruto's naivete in some ways could be both a point of clash and blend with Harley Quinn. She might see his innocence as something to take advantage of at first, but as she gets to know him, it could remind her of a part of herself she lost. Her jaded view of the world could make Naruto more aware of the darker aspects of life outside of his ninja world. Overall, their personalities would create a complex dynamic that could be explored in many different ways in fanfiction.