One common theme is exploration. Since Sora is used to traveling between different worlds in his own story, and Ariel has a sense of adventure in exploring the human world, their fanfics often involve them exploring new places together.
There's also a fanfic titled 'Under the Sea with Sora and Ariel'. In this one, Sora is transported to Ariel's underwater kingdom. Ariel shows Sora around her world, introducing him to all her friends. The story focuses on their cultural exchange and how they learn from each other's worlds, with a hint of a budding romance between them.
Well, I've read one where they go on a journey to find a lost charm that has special meaning for their relationship. It was really sweet as it showed how much they rely on each other and their growing feelings. You can try searching for ones with high ratings and positive reviews to find a good Sora x Kairi fanfic.
One great Sora x Kairi fanfic is 'A Journey of Hearts'. It beautifully explores their relationship as they go through different adventures in the worlds they visit. The author does a wonderful job of portraying their deep connection and the growth of their feelings for each other.
One common theme is adventure. Given Sora's nature from his original story, fanfics often put him and Elizabeth in exciting adventures. Another theme is friendship turning into love. They start as friends or allies and gradually develop deeper feelings for each other.
The writing style matters a great deal. Vivid descriptions of their emotions, like Sora's determination to protect Kairi or Kairi's love for Sora that she might be shy to express at first. Using the right words to convey the depth of their feelings and the beauty of the settings they are in, whether it's a magical kingdom or a serene beach, can make a fanfic truly engaging.
It's not appropriate at all. Such content is not suitable for public consumption and goes against the general norms of decency. Moreover, it may also be in violation of the original creators' intentions for the character of Ariel.
One possible plotline could be that Ariel and the urchin are from different worlds and they have to overcome various obstacles to be together. Maybe there are cultural differences between their species that they need to navigate.
One possible plot could be that Ursuala and Ariel become friends despite their differences. Maybe Ursuala, known for her dark magic, uses her powers to help Ariel when she gets into trouble in the ocean that normal mermaid abilities can't handle. For example, a new kind of sea monster threatens the mermaid kingdom, and Ursuala's magic is the key to defeating it.
Imagine that a dark force is spreading across the ocean, making the waters murky and the sea creatures sick. Moana notices this on her travels and Ariel also experiences it in her underwater world. They both independently set out to find a solution. By chance, they cross paths. At first, they have some misunderstandings due to their different ways of life - Moana is a human used to the surface world and Ariel is a mermaid from the underwater world. But they soon realize that they need to work together. They follow a series of clues left by an ancient sea spirit. Along the way, they learn about each other's families and the unique traditions of their homes. Finally, they find the way to defeat the dark force and in doing so, bring new hope and harmony to the ocean.