Quick answer — Sara Nakayama voices Riku Harada in D.N.Angel, Midori Chitose in Green Green, Kumiko Fukada in GTO: Great Teacher Onizuka and 6 more characters.
Sara Nakayama voices Riku Harada (D.N.Angel), Midori Chitose (Green Green), Kumiko Fukada (GTO: Great Teacher Onizuka), Helena (Spice and Wolf II), Mai Zaizen (The Melancholy of Haruhi Suzumiya), Mio Imai (Ghost Stories), Porche (One Piece: Adventure of Nebulandia), Miyu Tamaki (Alien Nine) and 1 more.
Riku Harada is voiced in Japanese by Sara Nakayama.
