Dataminers have located evidence that a character from the Rhythm Paradise franchise was originally planned for Super Smash Bros. for Nintendo 3DS and Wii U.
Hidden within the game's code is data for an emblem called "rhythm". The Cutting Room Floor user PushDustin, who reported the discovery, notes that this data exists among other characters rather than in data for stages or trophies, fueling pre-release speculation that the "Chorus Kids" from the Rhythm Paradise minigame "Glee Club" would be included in the game.
Found hidden within the stage emblem data are two files called "plankton" and "diary". While "plankton" is believed to be a leftover from Super Smash Bros. Brawl, specifically relating to that game's stage based on Electroplankton, several users on the series fan forum SmashBoards have hypothesised that "diary" may refer to a stage based on Nintendo Letter Box, the now-defunct messaging app on 3DS - Nikki, the Mii character who featured throughout the application, is actually the Japanese word for "diary".
More unused data found within the game refers to a character called Virus, found in the data among other stage bosses such as Ridley and Metal Face, leading many to believe that a stage based on Dr. Mario was intended to be included in the game, with the game's viruses appearing as stage bosses.
Beyond these unused filenames, no models are images are available for these files and as a result it is important to note that the actual uses of these unused items is unknown.