"Nightmare - Yume Nikki" is a 16 minutes long video game rip of the song "Nightmare" from the game Yume Nikki.
Instead of using an actual song from the game, the rip features a recording of someone playing the game.
From there, the player is trying to trigger the Uboa event. When the player enters Poniko's room and switch the light off, there is a 1 in 64 chance that the Uboa event occurs. Sounds of the player entering, leaving the house and switching off the light can be heard, along with the music changes. It lasts 6 minutes.
At 14:21, the Uboa event finally occurs. At 14:24, "GO MY WAY!!" from THE IDOLM@STER can be heard, but with the Uboa sound effect.
- If you sped up at the rendition of GO MY WAY!! with the Uboa sound effect, you'll hear an audio of Filthy Frank saying: "You just got pranked bro! Haha!"[reference needed]