Here is the link...
http://www.angelfire.com/anime2/omutsu/smd.html
This has to be my favorite diaper story of all, and it's really well done Sailor Moon fanfiction as well.
The author calls himself/herself Incognito Himitsu, and I really can't tell from the overall website if this person is active anymore or not.
In any case, the subtitle - "The Power of Shame, Embarassed Sailor Warriors" reads just like an episode title from the anime. And in this particular story, only the Inner Senshi are featured. Tuxedo Mask, Chibiusa, and the Outer Senshi do not appear at all.
A quick synopsis... a villain named Empress Platinum, whose description is quite reminiscent of Queen Beryl, arrives on Earth with aspirations of ruling the planet. To do this, of course, she needs to collect energy - like any classic Sailor Moon villain. Platinum's henchman Lord Copper deduces they can siphon off energy from shameful emotions of teenagers induced by making them wet their pants! A slew of shenanigans ensue resulting in Usagi and most of her friends wetting their beds and eventually even their panties, and being diapered by their moms, school nurse, etc... with the adults seeming to think that diapering teenagers for wetting problems is perfectly normal! Eventually Luna and Artemis suspect the wetting/diapering "epidemic" is being caused by an attack from a new enemy, and it's up to the Sailor Senshi to take on Lord Copper and his nefarious scheme. The story culminates in a slam-bang battle scene that does seem lifted right out of a Sailor Moon episode. There's even a surprise twist at the end, with Usagi being the butt of the last joke, which is 100% in character for a Sailor Moon episode, especially from the early seasons!
What makes this story so great, aside from the diapering & diaper wetting content, is that the plot structure and descriptions feel very true to anime. It really reads like the script of an actual episode, aside from the diaper theme. The characters are, for the most part, accurately portrayed. (I believe this story is from long before the new Viz dub, so the characters don't always sound *exactly* the way I feel they should, but the differences are minor at most.) My only major criticism is that Sailor Moon herself is not portrayed as heroically as I feel she should be. Yes, she is a comedic character and often the butt of the joke, but she is also a plucky and determined heroine who always comes through when need be. And I feel the latter part is sadly omitted from this story.
Even if you're not a big Sailor Moon fan like I am, if you like adventure to stories with any cute anime girls in diapers at all, then I highly recommend Sailor Moon D!