There's no way to tell just from the phrase 'kids in 99 story'. If the '99 story' is a fictional narrative, like a fairy tale or a fantasy story, then the kids are fictional characters created by the author. On the other hand, if it's a story based on real - life experiences, for example, a story about 99 kids in a real - life situation like a school or a community, then the kids could be real.
We can't determine whether the kids are real or fictional without more information about the '99 story'. It could be a work of fiction where the kids are part of an imaginary world, or it could be a true account where the kids are real individuals. For instance, if '99 story' is a story about a historical event involving kids, then they are real. But if it's a fictional story like a children's bedtime story, then they are fictional.