One common theme is friendship. Since Rangiku has a lot of friends in the 'Bleach' universe, fanfictions often explore her deep bonds with them, like with Ichigo or Renji. For example, stories might show how she helps them through tough times.
I'm not sure specifically as there could be many different takes on it. But it might be a fan - created story where Naruto is somehow the son of Rangiku, perhaps involving some sort of crossover or alternate universe concept where the Naruto and Bleach universes collide in this strange family relation way.
Often, it features the development of an unexpected relationship. Since Ichigo and Rangiku are from different backgrounds in the original story, the fanfic will show how they bridge those gaps.
You can try looking on some popular fanfiction websites like FanFiction.net or Archive of Our Own. They usually have a wide variety of fan - made stories, including ones as unique as 'naruto son of rangiku fanfiction'.
There's also 'Rangiku's Adventure Beyond the Seireitei'. This fanfiction takes her on an exciting journey outside the known areas, full of new challenges and character development. It really expands on her personality and abilities.
In my opinion, both have their merits. The anime brings the characters to life with animation and sound, but the manga allows for more imagination and detail in the panels. It really comes down to what you value more in your entertainment.
Bleach is not a novel. It's more famous for its manga and anime versions. The manga format allows for a more visually dynamic and action-packed presentation of the story compared to a traditional novel.
One great 'ichigo x rangiku romance fanfic' is 'A Chance Encounter'. It beautifully depicts their relationship starting from a random meeting and how they gradually fall in love. The story is full of emotional exchanges and sweet moments.