User blog:Pihou/VOCALOID Piano Songs?

I made a blog asking for help with marching songs be fore, but now I need some help  finding VOCALOID songs based around the sound o f the piano! :-D

I do not mean song covers where they are piano versions o f VOCALOID songs, but songs that are already based around the piano. Hiari, Hirari is the best example I can think o f, but I cannot  find other songs that are solely based around piano or mostly piano. Help, please? I need to  find more  for research since I want to write many piano songs  for VOCALOID as well! Thank you! :-)

Here is the list so  far:

- Hirari, Hirari