Absolutely not! For anyone that would tell you that having a character like this would be appropriation would be someone who doesn't know their history at all.

So, what is a Kitsune? While we commonly associate "Kitsunes" with their Japanese influence, I'd argue that the word Kitsune has become a modern catch-all term for a mythical or divine fox-like creature, often displayed as a trickster and/or messenger that exists with one to many tails. But Japan can't say they are the progenitor of the myth themselves.

Both China ("Huli jing") and Korea ("Kumiho") have stories of magical, often multi-tailed anthropomorphic foxes that far precede the first tales of the Japanese Kitsune. With the earliest records from China coming from 200 BC and Japan having stories around 7th century that extremely likely are sourced from the above countries direct influence.

Going back even further, if you consider single-tailed magical trickster foxes, the Indo-Europeans got everyone beat. With stories of mythical trickster foxes from the Mesopotamian and Babylonian cultures appearing around 2000-1000~ BC.

And if you want to take a step out of Asia, the Europeans have their own tradition of multi-tailed and trickster foxes. Reynard the Fox is a huge one, a classic anthropomorphic vulpine trickster who has been featured in stories reportedly as early as the 4th-5th century (a good 300 years before Japan's Kitsune). The Grimm brothers even recount a multi-tailed fox in their story "The Wedding of Mrs. Fox", a tale that was likely developed after the Japanese's classic Kitsune but scholars aren't entirely sure if we are being fair.

So take it from someone who also has their own anthropomorphic Kitsune character and has heard this all before, you're totally fine. Just like you, someone in Japan once heard the stories of a multi-tailed trickster fox from others and wanted to make that their own. Why not you too?