Perhaps the Fem Kyuubi and Fem Bijuu are in love with Naruto in different ways. The Fem Kyuubi might see Naruto as a powerful partner, while the Fem Bijuu views him as a kind soul. This love triangle could create a lot of drama and interesting character interactions within the fanfiction.
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.
A possible plot could be that the Fem Kyuubi and Fem Bijuu have their own goals and motives that initially conflict with Naruto's. However, as the story progresses, they come to understand each other better. The Fem Kyuubi could be seeking revenge on a certain group, and Naruto has to convince her that there's a better way, while the Fem Bijuu might be trying to regain her lost power and Naruto helps her in unexpected ways.
One possible interesting plotline could be the development of Naruto's relationships with the female Kyuubi and other female Bijuu. For example, how he overcomes the initial differences and misunderstandings between them. Maybe at first, the female Kyuubi is distrustful of Naruto due to her past experiences, but as they interact more, she starts to see his true nature and they form a bond.
One idea could be that the female Kyuubi, banished from the village, forms a secret alliance with Naruto outside the village. They train together in the wild, and Naruto discovers new powers with her help. This could lead to a journey where they face off against old enemies of the village who are also after the power of the Kyuubi.
One plot idea could be that the cold Naruto is initially distrustful of the Fem Kyuubi. But as they interact more, he starts to see her as more than just a powerful being. For example, she could help him in a battle against a common enemy, and during that time, he realizes her loyalty and they begin to form a bond.
A possible plot is that the fem Kyuubi and Nibi gain the ability to take human forms permanently. Naruto then has to help them adjust to the human world. They go on adventures together, like exploring different parts of the ninja world that are usually off - limits. Along the way, they discover secrets about the origin of the tailed beasts and how they can use their powers for the greater good.
One idea could be that Naruto, in his godlike state, has to protect the Fem Kyuubi from other powerful forces in the Naruto universe. Maybe there are ancient evils that want to capture the Kyuubi's power for themselves.
One idea could be that Naruto, in his Kitsune form, discovers a hidden power within the Fem Kyuubi that they must learn to control together to defeat a new and powerful enemy. For example, a dark sorcerer who wants to capture the Kyuubi's power for his own evil deeds.
One plot idea could be that the Fem Kyuubi has a special connection with Naruto and Hinata. Maybe she can sense their deepening relationship and decides to use her power to protect them from an upcoming threat in the shinobi world. This could lead to a lot of action-packed scenes as they fight together against the common enemy.
One idea could be that the female Kyuubi helps Naruto gain unique powers. As part of the harem, she uses her fox - related abilities to protect Naruto from various threats. And Naruto, in turn, helps her understand human emotions better.
One idea could be a story where Kushina, with her connection to the Nine - Tails, helps the fem Kyuubi (in a more human - like form perhaps) and Naruto to understand each other better. Maybe they all have to work together to defeat a new threat that targets the unique bond between Naruto and the Kyuubi. Another plot could involve the fem Kyuubi having some sort of past connection with Kushina that gets revealed as they interact with Naruto, leading to a deeper understanding of their intertwined fates.
One plot idea could be that the fem Kyuubi has a human form and she and Naruto have to go on a journey to find a way to restore balance in the ninja world that has been disrupted by some dark force. Along the way, they gradually fall in love as they face challenges together.