One of the tracks used in Hanako Game's Long Live The Queen.
Artist: pierrotlunaire
Original Title: ピアノソナタ”カトレア”より「本当のカトレア」
You can find the albums where the soundtrack was taken from here:
http://www.dlsite.com/eng/work/=/product_id/RE061960.html
http://www.dlsite.com/eng/work/=/product_id/RE039584.html
http://www.dlsite.com/eng/work/=/product_id/RE063455.html
http://www.dlsite.com/eng/work/=/product_id/RE062508.html