In the quiet town of Inaba, a string of serial murders has baffled the police, who have made little progress. Amidst this unsettling atmosphere, Yuu Narukami relocates to the area to stay with his uncle for a year while his parents work abroad. He begins attending Yasogami High School, where he quickly becomes friends with Yousuke Hanamura, Chie Satonaka, and Yukiko Amagi.
One day after school, the group tells Yuu about an urban legend called the "Midnight Channel"—a TV show that supposedly airs only at midnight on rainy nights when the viewer is alone. Intrigued, Yuu decides to check it out that night. Instead of the expected broadcast, he sees the face of the next murder victim. Stranger still, he feels a strange pull toward the television, which sparks the curiosity of his friends and leads them to investigate further.
Yuu eventually tumbles into the strange realm inside the TV, a place shrouded in thick fog and filled with dangerous beings known as "Shadows." Convinced that this alternate world holds the key to the murders, the group forms the Investigation Team, determined to solve the mystery behind the horrifying incidents.