Everypony is telling us, “It’s so amazing you two got Princess Luna to be the Mare of Honor at your wedding! And Princess Celestia as a guest!”

Everypony is meaning, “How in Tartarus did you, two middle-class mathematicians of no apparent social connections, achieve the social coup of the decade, upstaging all of the Canterlot aristocracy and peerage?”

The short answer is, “We made friends with somepony lonely and hurting who needed a friend.”

The long answer? Well, Princess Luna has given me permission to tell you the story. The entire story. Even the dark bits, from her foalhood. Which, I warn you before you begin, are dark. But I promise the ending is happy—after all, look at our wedding pictures! Have you ever seen a picture of Luna with such a big smile on her face?

Sequel to A day in Canterlot Juvenile Court, but can be read independently.

Story inspired by a comment by Veylon at the prequel. Thanks!

Princess Celestia was sure that the day was going to be great. The Sun shone bright in the sky, the birds were singing, and nothing could possibly go wrong. That was, until she received some rather grim news concerning her sister.

She thought she'd been clear enough about things last time.

Polish translation by Dolar84.
Spanish translation by SPANIARD KIWI.
Audio reading by Pony&Wolf Productions.

Celestia travels to a far corner of her kingdom to investigate a rumor about a colt with strange, illicit cutie marks. She meets Radish Root, a boy whose marks make him an anomaly in the fabric of Equestria, a mystery to himself, and an outcast among society.
When Radish joins the Royal Guard just prior to the return of Nightmare Moon, he finds his life being complicated by all the changes coming to Equestria. His marks will lead him into adventure, intrigue, and trouble... but will they ever lead him to answers?

Proofreader: Slavenger Karl
Cover Art Gallery
Table of original characters
A reader is translating this story into Spanish. Check it out here.

Equestria is growing, and magical savant Twilight Sparkle is disgusted by the crime and corruption this change has brought. Her life is changed forever when she discovers the Death Note, a notebook with inexplicable and deadly powers. She uses this book to pass judgement on those she deems unworthy of life, aiming to create a perfect world free of crime. But when the two Princesses put their best pony on the case, a mysterious detective known only as L, a psychological game of cat and mouse erupts between the two.
Comments contain spoilers. Artwork by blu-red, opening by Anon3mous. Now with its own TV Tropes page.

Twilight isn't having a very good day. An experimental spell blew up in her face, an army of changelings is attacking Canterlot, and she just died. Yet somehow, it looks like it's going to keep going downhill from here.

Given the chance to correct what's gone wrong, Twilight swears she's going to fix all this even if it kills her. Which it will. Frequently.

Cover art by Pixel Prism
Spanish Translation
Series TV Tropes page

Celestia and Luna have lived long and suffered greatly. Luna, still insecure in her newfound grace, is anxious to secure herself against any further suffering. She sees in Twilight Sparkle (and in many others) the roots of ten thousand tragedies. Celestia proposes a wager.

A very loose retelling of the Book of Job.

After thousands of years of ruling over Equestria and the umpteen amount of changes in social structure over that time, Celestia and Luna discover that they do not understand their subjects as well as they used to. After all, it's been several millennia since they were like every other average pony.

However, that's about to change when an eavesdropping Discord comes up with a "brilliant" idea.

How will the lives of the two sisters change? Will the lives of their new personas "Color Craft" and "Lyrical Rhapsody" be better than their old ones? Will the friends they meet along the way be too good to leave? And most importantly, will Discord ever be pretty?! No, probably not.

Artwork by wildberry-poptart on Deviant Art
http://www.deviantart.com/art/Teenage-Luna-and-Celestia-424486014

Featured: 1/19/2015 - Thanks!

Finally, after years of begging, Celestia gives Twilight permission to access the Forbidden Wing of the Royal Library, a wing so secret even the other princesses can't access it. Twilight rushes to Canterlot, excited for the research potential.

Then she finds those books…

(There's an FAQ here. Please read that before commenting.)

On the eve of the Coexistence Carnival - one of the most important celebrations in the world, where each and every kingdom comes together one night in peace to celebrate unity - Celestia (and Luna, I guess) accidentally reveals a secret about themselves.

Or, rather, reveals an accidental secret.

Rated teen because of one utterance of the f-word and one utterance of the b-word.

*Edit*
Wow! What a great response! I also went through it and changed a few wrong words here and there, an awkward sentence at another spot. Nothing major.

I can't believe this got featured! Celebration!

After Celestia humiliates her at a dinner, Luna storms off and ends up snooping around in her sister's room. There, she stumbles upon the journal Celestia kept immediately after the banishment of Nightmare Moon.

Cover art by bunnish on dA.
This story now has a reading by Craft Arts. Go check it out!
Featured on Equestria Daily on August 22, 2013.