Vagina Expansion

On the surface, it's somewhat entertaining to see the expansion aspect of it and the creative interpretation (seems like it will reach an ultimate limit when it takes over enough of her body that she can no longer speak to tell lies, rather than simply growing indefinitely), but the story itself is unfocused. You would assume it's a lesson in telling the truth, but with it progressing so quickly and the antagonist nowhere to be found yet, it has a natural dead-end in sight.

To be successful, it needs to slow down her change so that she can reflect on it, or alter the mechanism so it can grow indefinitely, allowing her to interact with her classmates as they explain why her suddenly massive genitalia aren't surprising to them. To generate rapport with the audience, she also needs someone to interact with socially about the issue, such as a lover or friends who she can bring herself to show it to.