Definitely the Naruko clone herself. Then there could be Sasuke. He might be intrigued by the clone and try to understand her existence. Also, Kakashi could be involved, maybe as a mentor figure to the clone, guiding her. As for the 'lemon' side, there could be some random attractive ninja from another village who catches the clone's eye and they develop a romantic relationship.
Well, in this kind of fanfiction, the main character would be the Naruko clone. Naruto could also be involved, as he might have complex feelings about the clone of his friend. Sakura could be there too, perhaps being jealous or curious about the clone. And for the 'lemon' part, a new, original character could be introduced, like a handsome rogue ninja who sweeps the Naruko clone off her feet and they have a passionate love story.
The father of the baby would be a key character. It could be a fellow ninja or someone from her past.
Her friends are likely to be part of it. A close female friend could be like a pregnancy buddy, sharing her own experiences if she has any. There might also be a mentor - like figure, an older woman who has been through pregnancy and can give Naruko valuable advice on everything from childbirth to raising a child.
Well, in a Naruko Clone Lemon fanfiction, the plot could involve the clone being created for some devious purpose by an enemy. But instead of following the enemy's orders, she rebels. She then meets a group of outcasts who teach her about real friendship. Regarding the 'lemon' part, it could be that she falls in love with one of the outcasts and they share some steamy, passionate moments as their relationship deepens.
Sakura could be a potential character. She has a long - standing relationship with Naruto, and in this harem scenario, she might be jealous of Naruko at first but then come to accept the situation. Hinata could also be part of it. Given her love for Naruto, she would be an interesting addition to the harem, adding a shy and gentle dynamic.
Obviously, Aria herself is the main character. Her family members like her mother and father could be important characters, offering support or having different opinions. Her best friends would also be likely to be involved, providing emotional support or getting into some friendly arguments about how she should handle the pregnancy.
It could be an evil scientist who created the clones for his own malicious purposes. He might want to use their power to take over the Hidden Leaf Village. This antagonist would constantly be trying to control the clones and use them as weapons.
Well, there could be her best friend who is always there for her during the pregnancy, giving her advice and emotional support. There might also be a mysterious figure, like an old wise woman who has knowledge about pregnancies in special circumstances that Tera Faya's case might be. And of course, there could be a rival of some sort, who might try to use her pregnancy against her in some way.
Igneel could also play a role. Since Igneel was Natsu's adoptive dragon father, he could appear in Natsu's mind during the transformation, guiding him and giving him advice on how to handle his new dragon powers. And there could be other dragons in the story as well. They might be either friendly or hostile towards Natsu depending on their nature.
There could also be new characters introduced. Maybe other magizoologists from different parts of the wizarding world. They could have different approaches and beliefs about magical creatures. Some might be rivals, trying to outdo Harry in the discovery and study of new species, while others could be mentors, guiding him in the complex world of magizoology.
Obviously Ranma herself. Her father Genma could also be a major character as he has to deal with his daughter's new permanent state. Akane could be there too, and their relationship would likely be very different. Instead of the typical boy - girl rivalry, it could turn into a more complex female - female dynamic.