Yukie Nakama, Asaka Seto
Brilliant brain surgeon Fuyumi Hiyama has been called upon by medical coordinator Towako Nakahara to perform surgery on a female high school student. She has Spontaneous Occlusion of the Circle of Willis, on which Fuyumi has conducted research. Fuyumi carries out the surgery using a new surgical technique that she herself devised, but the patient's condition suddenly worsens and she dies mysteriously. After that, unusual incidents continue to surround Fuyumi.