Well, first off, Minato is a must - he was her partner in life. Then, there could be other female kunoichi who were her comrades or rivals. This could create interesting storylines. The Nine - Tailed Fox could also be an important character in a way. Since it was sealed within her and then Naruto, it could have some sort of spiritual or physical connection to her that could be explored in the fanfic.
Minato would be an obvious choice as he was her husband. Jiraiya could also be included as he was Minato's teacher and might have had some interactions with her. Kakashi, being an important figure in Naruto's life, could have some connection to her in the past as well.
Jiraiya could be important. He was Naruto's mentor and knew Naruto's father well. He might have some stories about Naruto's parents that could add more depth to the meeting. Maybe he could be there to witness the encounter between Naruto and his mom and share his insights.
Obviously, Naruto and Big Mom would be main characters. Naruto would be the one to oppose Big Mom if she was causing trouble in the Naruto world. His determination and never - give - up attitude would be pitted against Big Mom's powerful and often - cruel nature.
Grover could be a popular character. Since he's Percy's best friend, he might be involved in the fanfiction, perhaps helping Percy protect his mom or going on adventures with them. Another could be Annabeth. Her intelligence and skills could be useful in the stories, like when they are facing a difficult situation and she comes up with a clever plan.
One of the well - written Naruto's mom characters in fanfiction is the one who is portrayed as a strong - willed and intelligent woman. She might be shown as having a great influence on Minato's decisions even before Naruto was born. Another could be the version where she has a hidden past filled with secrets and mysteries that gradually unfold as the story progresses. And there's also the one where she is depicted as a very loving and gentle mother figure, which is a contrast to the tough world Naruto grows up in.
Rock Lee would be an energetic and passionate character to include. His never - give - up attitude would be inspiring to the OC. He could constantly challenge her to be better and his pure - heartedness might make him quickly fall for her. Neji could also be in the harem. His initial rigidity and belief in destiny could be challenged by the OC's free - spirited nature. And then there's Kiba, with his love for his dog Akamaru. His straightforward and somewhat wild nature would bring a different flavor to the relationships in the fanfiction.
The father could also be a character. He might play a role in either supporting or contrasting the mother's love. For example, he could be the more practical one while the mother is more emotional in dealing with the upcoming situation in the story. Or he could be equally loving and they work together as parents.
Iruka - sensei. He was Naruto's first teacher and has a connection to Kakashi as well. He could provide some emotional support or some important backstory information that helps Naruto and Kakashi in their journey in the fanfic.
Sasuke could be one of the main characters. He might be initially skeptical or even hostile towards Naruto's mermaid side, but as the story unfolds, he could come to understand and support Naruto. Another character could be Sakura. She could use her medical ninjutsu skills to help Naruto if he gets injured during his underwater adventures.
The main characters are obviously Naruto, his mom Kushina, and his dad Minato. Naruto is the protagonist of the Naruto series, and in this fanfiction, his parents play important roles in his life, whether it's through memories, time - traveling encounters, or spiritual visitations.
Samul, of course, since he's Naruto's supposed father in this fanfic. He could be a powerful ninja who had some great influence in the past. Another character could be Naruto's mother, who might have a different story now considering her relationship with Samul. Also, characters like Jiraiya could still play an important role. He might be the one to guide Naruto in understanding his new identity as Samul's son and help him train to face the challenges that come with it.