Welcome! I would like to found a new story branch inspired by the open world founded by Jon Sleeper/Jon Buck, Winds of Change. If you would like some really good transformation storywriting, feel free to find one of their archives, of which I think there are at least two. It is beautifully written material.
In this universe, the Earth as we know it has, a little more than a generation ago, become the victim of a strange time-traveling incident. A small furry universe (long story) collided with ours, and the incident destroyed that universe utterly, causing the deaths of untold billions of billions of inhabitants.
The story gets stranger, though. The substance and--if you will--"soul" of the furry universe could never truly die, and as the broken pieces of splattered into ours, all adults on Earth began to change into animal-like beings (furries/anthros).
However, the pattern of the change has was uneven, causing some to change only their ears or eyes and causing others to become almost completely animal, often losing (especially if completely changed) their sensibility and remaining "feral" until having gone through a painful rehabilitative process to recover bits and pieces of their sanity, sometimes only recovering partially and being left a pathetic shell of what they once were.
As if growing up were not hard enough, puberty--therefore the onset of sexual maturity--is now accompanied by a child physically changing in the same manner. Instead of looking for their "cutie marks" like the children of a certain cartoon series, THESE young teens look for the first evidence of change. The changes are looked upon with a mixture of pride and anxiety, and kids sometimes...although surprisingly rarely...feel very unhappy with what they become, taking as much as years or lifetimes to truly accept their fates. Most of the time, they are relieved to finally see their first sign, though.
Oh, and some changes are transgender, which is ALWAYS a source of confusion...and sometimes warrants seeking out help to reverse that part.
Finally, another important aspect of these changes is that some people now develop superpowers as a consequence of their changes. Most of them are very unremarkable and often altogether impractical, and the most common is the ability to change completely into a full-blown animal at will without necessarily going feral. In rare cases, kids grow up to be polymorphs, and in other cases, they grow up to have Hulk-like strength, an empathy talent, telepathy (which can be unidirectional), or (more often) something almost shockingly useless (except when it's not).
So whose story shall be told, then? Feel free to add others.