Kentaro Sakaguchi, Mei Nagano, Rio Uchida, Noriko Eguchi, Ryohei Otani, Masanobu Takashima
6 from IMDB
On-call substitute doctor Shugo suddenly finds himself faced with a terrifying criminal in a clown mask. The assailant demands that Shugo treat injured high school student Hitomi. The perpetrator sets siege to the building and Shugo finds himself confined with 64 unknown patients.