[hyl]

Seeing that you don't mind music from VN's, because of Grisaia in your list i can recommend most of the instrumental tracks of the Hatsyuki Sakura OST like

桜の心 http://www.youtube.com/watch?v=FxSh7RtdrVE
送る言葉 http://www.youtube.com/watch?v=B2YLdbCMKVw
ナイトダンス http://www.youtube.com/watch?v=VFA5A7ErRjw
死者の嘆き http://www.youtube.com/watch?v=fFuo6BiIfQU