Eiji Yokota

Out of the blue, monsters usually living beneath the Earth’s surface began to attack the terrestrial world. They were called the Underground Hades Empire Infershia. The Ozu Siblings of Makito, Houka, Urara, Tsubasa, and Kai hear from their mother, Miyuki, that they are the Magicians of Justice to stand against the Infershia. The siblings are perplexed by such an unexpected event. However, without hesitation, Miyuki charges at the Infershia, and the Ozu Siblings are forced to come together to fight as one.

MUSICAL BIOHAZARD ~ Voice of Gaia ~ is set in an unspecified year where the threat of bioterrorism has continued to increase in extremity. Much of the story is set in and around the walled Croatian city of Dubrovnik, on the Adriatic seacoast, which faces attack from "Them", zombies infected by an ancient virus. The survivors in Dubrovnik are protected by both their wall and by music, as melodies are known to calm Them, surprising their violent urges.