I think Misty from the Pokemon world could be a main character in this fanfiction. Since she has a connection with water - type Pokemon, she could easily fit into the underwater world of The Little Mermaid. Along with her, a Psyduck would be there. Psyduck's clumsy yet powerful abilities could add an interesting element to the story. And of course, Ariel would be a main character. She could learn a lot from Misty about the Pokemon world and they could team up to protect both their worlds from any threats.
Prince Eric could be a main character. He would be important as he is Ariel's love interest. Also, King Triton, Ariel's father, could play a significant role as he would be concerned about Ursula's return and want to protect his daughter and the kingdom.
Obviously, Ariel would be one of the main characters. She'd be the mermaid trying to navigate high school life. Eric could also be there as the love interest. Maybe Flounder could be her sidekick, a fish - out - of - water (literally) in the high school, always getting into comical situations. And Ursula could be the school bully or the antagonist who tries to make Ariel's life miserable.
A sea - faring cat could be a new character. This cat has a special bond with the sailors on Prince Eric's ship. When Ariel comes on board, the cat is immediately suspicious of her. But as time goes on, they form an unlikely friendship, and the cat helps Ariel understand some of the human ways that the sailors have.
Maybe a lost princess from a sunken city. She has been in hiding for a long time because of some danger that destroyed her city. She meets the little mermaid and they become friends. The lost princess has unique powers related to the ancient magic of her sunken city, and she shares these powers with the little mermaid to help her in her quests.
For a 'Little Mermaid Naruto fanfic', Naruto and Ariel are the primary ones. However, Gaara could be an interesting addition. His past of being an outcast could parallel Ariel's feeling of not fully belonging in her own world sometimes. Then we have Ursula, the sea witch from the Little Mermaid story. In this fanfic, she could be a powerful enemy who wants to use Naruto's chakra for her own evil purposes. And Hinata could be another character, her shy nature contrasting with Ariel's more adventurous spirit as they both interact with Naruto in this unique crossover.
The main characters could be the mermaid herself, who is now a young woman with a passion for ocean conservation. And then there could be a male scientist who is researching the effects of climate change on the ocean. They meet during a research expedition and form a connection.
Obviously, Lily is one of the main characters. She's the mermaid around which the story revolves.
Obviously, the Little Mermaid herself would be a main character. She could be joined by her friends from the sea, like a talkative seahorse or a wise old octopus who gives her advice from afar. At Ever After High, her roommates or classmates like Apple White or Raven Queen could also be important characters. They could help her adjust to school life on land.
A mermaid named Nami could be one of the main characters. She might be a curious and adventurous mermaid who is the first to approach Naruto. Another could be Marina, a more reserved mermaid but with great wisdom. She could act as a sort of advisor to Naruto within the mermaid world.
The main character in 'Little Mermaid 2 Story' is surely Ariel's daughter. She is the protagonist, and her story is the core of the plot. Ariel and Eric play important roles as her parents, providing guidance and love. There could be a wise old turtle or a helpful dolphin as her animal friends. There might also be a rival mermaid who is envious of her or a sea monster that she has to face. These characters all contribute to the rich tapestry of the story, making it an exciting follow - up to the original 'Little Mermaid' story.