"Meanwhile, a series of suspicious suicides are reported in town. A team of top-secret undercover agents is dispatched to investigate.

"On the Ginza subway line -- the last train heading toward Asakusa, a girl sits quietly in a dreary subway car.

"Her name is Saya. With a piercing gaze that would force even an adult into submission and lips tightly drawn with determination, she is the savior sent by the 'organization' to vanquish the blood-sucking chiropterans that have concealed themselves among their human hosts.