Sixty years ago, a strange epidemic of sleeplessness struck, causing people to remain awake for over a week and eventually descend into madness from lack of rest. To treat this condition, a new drug was created, but it unexpectedly turned those who took it into vampires. A conflict erupted between humans and vampires, and humans ultimately won, though some vampires managed to survive. Mi Liu, known as "The Child of Hope," is the child of both a human and a vampire, representing the potential for peace between the two races. After a carefully orchestrated bank robbery, Mi Liu is captured and sent to a special prison run by the National Defense Agency, built to contain vampires. During an escape attempt alongside Anji, Mi Liu encounters mysterious creatures and learns that the prison is constructed on top of the vampires' birthplace: what used to be the capital city, Blue Town. The heroes must uncover the reason vampires are imprisoned in Blue Town and figure out what the strange monsters attacking them truly are.