http://www.oaks-soft.co.jp/princess-soft/quartett/
Quartett! Released in Japan in 2006. Hentai Game by Littlewitch productions.
98 Musically talented members all around England are gathered into one palace for the world's greatest musical competition in the world.
Each member is to create a group of 4 or 5 and to compete in the musical campitionship.
But like always in a littlewitch production, nothing will go as planned. ^.^
If it is possible, a PC version would be very nice.