[FP] Concerned about the characters.

So, I had this story adapted in an upcoming animated movie. So the animation studio reached out to me and wanted to create two new characters for this movie. The two new characters are a brother and sister.<br><br>So I just want to confirm, if I wrote a story that has two characters, those characters belong to me? If someone else comes in and creates two new characters for the story I wrote, does that automatically mean I own those as well? Because I'm also being told that this animated movie is also copyrighted, adapted from my story.<br><br>EDIT: I like to add some more information. So the story itself was written 10+ years ago. I wrote it on my own, and I am the copyright owner. I have an idea of what the characters look like and what personalities they have. I was contacted by an animation studio in 2022 to adapt my story. I was asked questions like how I see the characters acting, talking, etc. I was even asked to provide voice samples for some of the characters. This is pretty much every information I gave for the characters. In 2023, an animated movie was released and had two new characters in it. No one told me about the new characters being added. Both characters also share the same personalities as my characters, but not exactly. But overall, pretty close.