The story begins in the near future, where a social mobile network
called the "Kizuna-Topia" (Bonds-Topia) controls all communication and
surveillance in the wall-bound city.
In this city, two sisters, Enna
and Yayako, come face to face with the ongoing man-hunt for young,
healthy children. The kidnappers take these kids to the white tower to
extract their brains and sell their bodies. This man-hunt, led by the
local police known as the "Jikei," is counteracted by the mysterious
being only known as "The Witch." Enna, Yayako, and other residents of
this city are trapped between the ongoing conflict between the Jikei and
The Witch.