If you are looking to play this content today, you generally have two legal and technical routes, provided you own the original game data.
For those using hardware like a Japanese 3DS or the Citra Emulator , specific steps are required for the DLC to function:
Navigate to SD -> cias . Select the base game CIA and choose "Install and Delete CIA."
When files are dumped directly from a Nintendo 3DS system, they are encrypted with proprietary Nintendo security keys.
You can no longer purchase or download the DLC legally through official channels.
The DLC for significantly expands the music library, which is critical for a rhythm-focused title.
The core game includes around 20 songs, but its true value lies in the extensive DLC that added a massive, vibrant song list.
The result? A complete, playable version of My No.1 Stage with every premium dress, song, and event card—even on an American or European 3DS that has never touched the Japanese eShop.