I've never heard anything as awesome as this.
This is totally masterpiece.
AND IT'S AN IMPROVISATION.
It's a shame it's only got 4.16, so not many people can find it(as I know most of people only check up to first 7 pages of songs). It deserves a full 5.
Damn, I'm in loss of words. I want to write tons of good things about this piece, yet I can't find anything that could describe it. It's THAT awesome.
If I was ever asked about best piano song I've ever heard, I would surely say "Piano Study of a Dream by Nekoprism".