Natsuki Hoshino (Hotaru Hazuki), a blind woman, is present at the scene when her best friend Yoko (Guriko Yamanote) is brutally murdered by a obsessed stalker named Yûichi Mizuno (Yûya Ishikawa). Although Natsuki cannot visually identify the killer, she remains the sole surviving witness to the crime. Realizing that Natsuki could potentially recognize his voice or presence, Mizuno begins stalking her through the dark, planning to eliminate her to cover his tracks while engaging in predatory psychological and physical intimidation.