Captain Bra and Panties
Anna wanted her and Elsa to fight crime in Arendelle as superheroes. Because she was inspired by the Captain Underpants books, there would be no shirt or pants. Instead, just pink and blue bras, some matching underpants, capes, and masks. They managed to stop Hans and the Duke of Weselton from stealing tradable goods from Arendelle. Request from mreccentric.
Naked Pit and Palutena Meet a Naked Lucina
Sometime after the events of Fire Emblem Awakening, Lucina ended up in Skyworld, naked as a jaybird. There, the nudists known as Pit and Palutena welcomed the bare princess with open arms (but not before verifying that she meant them no harm). Now Lucina wants to live with the nudist angel and goddess as their adopted daughter. Don't read if you hate futa. Request from Jam-Man 265. Also on AO3.
Knuckles and the Secret Nudist Colony
An 18-year-old Knuckles stumbled across Rouge, Amy, Cream, Vanilla, Sally, Fiona, Bunnie, Blaze, Lien-Da, Shade, Mina, Honey, Nicole, Sticks, Zooey, Cosmo, Millie, Barby, and Wave, who all practiced nudism in secrecy as adults and invited him to be part of it. Request from corinacantu1224 and another person who wanted to be anonymous.
Naked Pit Reimagining
Essentially, in this reimagining of Naked Pit, the plotline would be similar to the 3DS game, except that Pit and almost every god and goddess (that has a human form anyways) are already naked, this would be because all godlike entities are beings of a higher existence and therefore don't need clothes (sort of like how Adam and Eve were before they bit the apple). Request from Jam-Man 265.