Definitely not true. Rikki Tikki Tavi is a work of fiction. It was crafted to bring adventure and imagination to the readers, not based on real events or people.
Maybe the Wolf Kwami has a special power that is different from the other Kwamis. A new villain wants to steal this power for their own evil plans. The story could focus on Ladybug and Chat Noir protecting the Wolf Kwami and its power. This would involve a lot of action and adventure scenes.
I'm not sure specifically as there could be many different interpretations in such a fanfiction. It might involve Naruto somehow coming into possession of a kwami, perhaps leading to new powers or adventures. Maybe he has to deal with the responsibilities that come with having a kwami, like a Miraculous in the Miraculous Ladybug universe.
Let's make a Kwami named Luma. Luma could be a Kwami related to stardust. Its Miraculous could be a star - shaped hairpin. The superhero with this Miraculous would be able to fly faster than normal superheroes, and also have the ability to create a shield made of stardust that can protect from most attacks.
Well, this kind of fanfiction could start with Marinette making a mistake while using the Miraculous. Then she finds herself in the form of a Kwami. She might be really tiny and have to find ways to get around. She could hitch rides on people's shoulders or use her small size to her advantage when it comes to spying on Hawk Moth. And she would definitely have to deal with the fact that she can't just transform back into her normal self right away, leading to all sorts of comical and tense situations.
Well, Tikki and Plagg are kwamis in the Miraculous Ladybug universe. Their love story is rather unique. They have a very old relationship. They bicker a lot like an old married couple. But beneath all that, there's a deep connection. They are two sides of the same coin in a way, with Tikki representing creation and Plagg representing destruction. Their love is shown through their understanding of each other despite their differences. They have been together for a very long time and have a bond that is hard to break.
One possible fanfiction could be about Marinette's daily life with Tikki. For example, Marinette could be having a tough day at school, getting bullied by Chloe. Tikki, being her kwami, tries to cheer her up by suggesting they make some special macarons. They then spend the evening in Marinette's room, sharing stories and laughing, which helps Marinette forget about her bad day.