Default system voice is done by Mizuhashi Kaori (Len). To unlock extra system voices done by other voice actors (selectable in the Special menu), repeatedly clear the Survival mode (meaning win 22 matches and go through the entire roster of playable characters) with Hisui & Kohaku.

Unlockable	How to unlock
1. Yuzuki Ryouka (Arcueid)	Clear Survival mode the first time.
2. Sakuma Kumi (Ciel)	Clear Survival mode the second time.
3. Hitomi (Akiha)	Clear Survival mode the third time.
4. Matsuki Miyu (Hisui)	Clear Survival mode the fourth time.
5. Takano Naoko (Kohaku)	Clear Survival mode the fifth time.
6. Mouzuki Miwa (Miyako)	Clear Survival mode the sixth time.
7. Natsuki Rio (Sion)	Clear Survival mode the seventh time.
8. Minami Oumi (Satsuki)	Clear Survival mode the eighth time.
9. Mitsuishi Kotono (Aoko)	Clear Survival mode the ninth time.
EX. Yuzuki Ryouka (Neco Arc)	Clear Survival mode the tenth time.