tsuki_no_waltz
月のワルツ ("Waltz of the Moon")
A 2004 song composed & sung by Isayama Mio. (Lyrics by Yukawa Reiko, Arrangement by Abe Jun)
Its anime music video for Minna_no_Uta was created by Ishizuka Atsuko.
See also
* Wikipedia article: Tsuki no Waltz
* Nicopedia: http://dic.nicovideo.jp/id/122663
* Minna no Uta (NHK)