Ayaka Ichijo is a graduate student with an IQ of 200 who tries to investigate the strange deaths happening nationwide after people supposedly watched a cursed video and her younger sister also did the same out of curiosity.
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.
A large monster attacks Japan, but dies suddenly. While the people rejoice and bask in relief, the giant corpse left behind begins to slowly rot and bloat. If it explodes, the nation will be destroyed.
