Ann Angel has assembled a collection of short stories about "secret selves" from a variety of YA authors, from established ones like Chris Lynch and Ellen Witlinger, to debut authors. Some of the secrets are obvious ones teens would face, like their sexual activities or their outsider quirks. A few of the stories have secrets that manifest in extraordinary ways, from guardian angels to secret spies.
Weakest: "We Were Together" deals with secrets and consequences in a truncated way that's pretty unsatisfying, like it was the start of a longer story that got cut short because of the length requirements. "The We-Are-Like-Everyone-Else Game" deals with toxic friendships and family secrets but the two don't coalesce as well (and maybe it's because I read a vignette about a family that deals with hoarding right before this and it pulled it off better).
Interesting: "Partial Reinforcement" and "When We Were Wild" convey the complicated nature of their main characters, and the conflicting interests of their story kind of transferred to my reading for it, but in the best ways.
Best ones: "A Thousand Words," "A Moment, Underground" and "Quick Change," I don't want to spoil anything about them, so I'll say "Quick Change" is the story I wanted more of the most. "A Moment, Underground" perfectly captured the moment of burying or keeping a secrets. And "A Thousand Words" was an amazingly constructed story of how secrets can be different things to different people.
Slightly off-tangent but worth reading: "Storm Clouds Fleeing From the Wind" is a gorgeous fairy tale set in a fantasy Japan. "Cupid's Beaux" is entertaining, but obviously scraped from the author's other series and clunky to read on its own merits because so much time is spent dumping worldbuilding exposition in it, but it's still intriguing for those who want to read more. "Little Wolf and the Iron Pin" is another fairy tale with some Bluebeard overtones, short and to the point so to speak.