There's only one explanation: kikiyama is youtube
could be some kikyama poser or youtube added kikiyama to their database of copyrighted songs (lol)
But Yume Nikki is freeware, this makes no sense.
FREEDOM ISN'T FREEEEEE
I really like the music in YN, and have also been supremely inspired by avant garde minimalist and ambient music in the past.
Two albums which I highly recommend to anyone interested in what might be able to be described as "Dark Ambient"
Naked City's "Absinthe"
Toby Driver's "In the L..L..Library Loft"
As with YN compared to most other games, these albums require patience for immersion.