Tsunade might also play a role. She could suspect Naruto of having a secret life and start an investigation. And of course, Orochimaru could be involved as well, either trying to use Naruto's secret for his own gain or being a part of the mystery that Naruto is trying to solve in his secret life.
There could be a mysterious mentor figure who guides Naruto in his secret life. This person might have unique abilities and a deep understanding of the ninja world's secrets. Another potential new character could be a spy from another village who discovers Naruto's secret life and tries to use it to their advantage.
Obviously Naruto as the main character. Sasuke could be there, and his relationship with Naruto might change due to Naruto's new identity. There could also be characters from the underworld, like minions of Hades or other mythological creatures.
Obviously Naruto himself. There could also be the other Naruto characters like Sasuke, Sakura, and Kakashi. And perhaps some Egyptian god - like characters related to Anubis, like his servants or other gods who interact with Naruto due to his relation to Anubis.
Obviously Naruto himself. Then there could be Athena, who might appear in some form, either as a guiding spirit or in flashbacks. His friends like Sasuke and Sakura would also be there. Maybe some Greek mythological characters like Hermes could show up to interact with Naruto, since he is now related to their world.
Well, obviously Hermione herself is the central character. But other characters could include her friends like Harry and Ron, who might be completely unaware of her secret life at first. There could also be new characters introduced, such as a mysterious mentor who is guiding Hermione in her secret magical activities. Maybe a powerful witch or wizard from a far - off land who has some connection to Hermione's family in the past.
Well, obviously Naruto and Hinata as Shinachiku's parents. His friends could be the children of other Naruto characters, like Boruto's friends. Maybe the son or daughter of Shikamaru could be his strategic partner in some adventures. Also, the new generation of the Akatsuki could be potential villains in the fanfic.
Obviously, Kurenai herself could be a central character in the harem. Also, Anko could be a potential member as she is associated with Kurenai and has her own unique personality. Hinata might also be involved as she has a crush on Naruto and could be drawn into this situation due to her connection with Naruto and the overall Naruto - Kurenai scenario.
Kakashi could be a potential swordsman character. He's known for his combat skills. In the harem, Hinata could be there. Her gentle nature would contrast with the action-packed world. Also, Ino could be part of it, using her mind - control jutsu in unique ways to protect the group and be involved in the harem's relationships.
Naruto himself could also be a main character. He could visit the Hidden Star Village and interact with the Hoshikage, getting involved in the village's affairs and helping them solve their problems. This would be an interesting way to incorporate the Naruto we all know into the fanfic.
There could be a hermit who takes Naruto in during his banishment. This hermit could teach him some ancient ninja techniques. Another new character might be a fellow outcast that Naruto meets, and they form a bond while living on the fringes of society.