In some fanfictions, Naruto's mother might be a character related to the Uchiha clan in a unique way. It could be someone who was secretly in love with an Uchiha and had Naruto as a result. Maybe she was a long - lost relative of the Uchiha who was trying to protect the clan's secrets through Naruto.
One of the popular mother figures in Naruto fanfictions is Kushina Uzumaki. In many fanfictions, she is often depicted in more depth, showing her relationship with Naruto in different scenarios. For example, some fanfictions might explore what it would have been like if she had survived and been able to raise Naruto. Another popular one could be Tsunade. As a strong female character, she can be seen as a mother figure in some stories, guiding and protecting the younger characters, especially Naruto at times.
Maybe it could be an existing female character from the Naruto series who steps into a motherly role for Naruto. For instance, Tsunade. She already has a sort of protective and guiding role in Naruto's life, and in the fanfiction, this could be developed further into a full - fledged motherly relationship.
In fanfiction, Naruto can be a father. The mother can vary greatly. There are fanfictions where Naruto has a family with different pairings. For example, if the fanfic takes a different turn from the canon story, he could be with a character who has a unique backstory and abilities. It all depends on the creativity of the fanfic author.
I don't know for sure, but it could be the mother herself, her children, and perhaps some of the well - known Naruto characters like Naruto, Sasuke, or Sakura who might be involved in the story related to the mother's sins.
There could also be a group that wants to use her child as leverage against her. They might see her love for her child as a weakness and try to manipulate her into doing things that go against her values or the safety of the village.
Maybe it's an adopted child. Naruto, with his big heart, could have taken in an orphan from one of the village's tragedies. This would give him the role of a single mother in a very unique way as he tries to instill his values and ninja skills in the child.
The main characters are surely Kurenai and Naruto. But there could also be other characters like Naruto's friends, such as Sasuke and Sakura. They might be involved as they interact with Naruto in his new relationship with Kurenai. Also, some of the older ninja like Kakashi could be part of the story, perhaps initially being skeptical about Kurenai's new role in Naruto's life but later coming to accept it.
It could be a random villager that Naruto met during one of his travels. Maybe she was from a small village that Naruto helped protect, and they had a brief encounter that led to the child.