If memory serves me correct, Hiyama Nobuyuki is voicing a character in Mnemosyne -Mnemosyne no Musume-tachi-, one that is unusual for him to play, I seem to recall.
Also, if memory serves me correct, Noto Mamiko commented that the role of Asougi Rin is a particularly difficult one to perform.
Every Japanese website which has covered Mnemosyne -Mnemosyne no Musume-tachi- in detail that I have visited (eg., goo, AT-X)
stresses that Yamanobe Sayara, head of Aoyama's Sayama Pharmaceutical Laboratory, is a
sadist.
Describing Sayara as a "considerably sadistic character" and commenting that she is happy to voice her, Tanaka Rie seems to relish playing evil, if not crazy, villains: Suigintou in Rozen Maiden, Tomoe Marguerite in My-Otome, Morganna in .hack//SIGN, Nomura in Higurashi no Naku Koro ni Kai, Helga Neumann in Phantasy Star Portable (PSP local multiplayer RPG), etc. As someone elsewhere observes,
"Rie Tanaka has one awesome evil voice."