One possible plotline could be Naruto struggling to come to terms with his half - bijuu nature while also dealing with his relationship with the fem bijuu. Maybe there are other characters who are either afraid or in awe of his unique state, leading to various conflicts.
In fanfiction, if Naruto is half - bijuu, it could mean he has enhanced physical abilities. For example, he might have greater strength and speed like a full - bijuu. His chakra reserves could also be much larger, allowing him to perform more powerful jutsu for longer periods.
The power dynamics could be complex. Since Naruto is half - bijuu, he might have some powers that are a blend of human and bijuu abilities. The fem bijuu, being a full - fledged bijuu, would likely have more raw power initially. But Naruto could have the advantage of being able to think more like a human and strategize better.
Yes, there might be. There are numerous fanfiction stories out there in the Naruto fandom, and with such an interesting concept as 'naruto is juubi x fem bijuu', it's quite possible that someone has written a story about it. You can check on popular fanfiction websites like FanFiction.net or Archive of Our Own (AO3).
In fanfiction, if Naruto is half - bijuu, his appearance could change in several ways. His ears might be a bit pointed, like those of a fox if it was related to the Nine - Tails. There could be a faint glow around him, especially when he gets angry or uses his bijuu - related powers. His nails could be longer and stronger, like claws. And his gait or the way he moves might change, becoming more like the way the bijuu moves. He might even have a faint, beast - like growl in his voice at times, which would be a very distinct change in his appearance and the way he presents himself.
There could be a relationship based on mutual respect. Naruto respects the power of the bijuu, and the fem bijuu respect Naruto's strength of character. It might start as an attraction from the bijuu side, but grow into a deep bond as they get to know each other better.
Naruto might be initially shocked. He has always seen the bijuu as powerful entities, not as potential mates. But being Naruto, he would likely approach the situation with his usual kindness and try to understand their feelings.
It could be an ancient sage. In Naruto lore, there are sages who have had a great influence on the world. An ancient sage could be the one who created or fathered the bijuu. Maybe he had some great power and knowledge that allowed him to bring the bijuu into existence.
One interesting plot idea could be that the Fem Kyuubi and Fem Bijuu form an alliance to protect Naruto from a new, powerful enemy. They use their unique powers and femininity to outwit the foe. For example, they could use their charm to distract the enemy while Naruto prepares a powerful jutsu.
The relationships could develop gradually. At first, Naruto might be a bit wary of the Fem Kyuubi and Fem Bijuu because they are so different from what he's used to. But as they fight together against common enemies, a sense of trust could start to form. For example, if they save each other's lives in battle, that would strengthen their bond.