Pretty sure this is done by Sasaki Mutsumi, since this is the front cover of one of the PS2 game's CD. (I'm not sure if VGMDB is good enough of a source for me to tag the artist, but the CD is called "FU・WA・RI告白! / 桜月キラ&ユラ、一条薫子&菫子、白鐘沙羅&双樹、千草初&恋、雛菊るる&らら、桃衣愛&舞" and has catalogue number LACM-4154.)