Theatrhythm box reveals paid DLC, 'Nintendo Network' logo
The front of the box also features a "Nintendo Network" logo, which hasn't been used elsewhere before. This is likely some kind of rebranding for the Nintendo Wi-Fi Connection, rather than a completely new service, but we'll certainly find out before the game's mid-February release.
Finally, the box identifies the genre as "Theatrhythm Action." That's just a bit on the nose.