Inaba is a sleepy countryside town that has recently been the center of a string of mysterious serial murders. While his parents head abroad for work, Souji Seta moves into the town to live with his uncle for the year. He enrolls at Yasogami High School, where he is placed in the same class as the bold Chie Satonaka, the rowdy Yosuke Hanamura, and the refined Yukiko Amagi. The four quickly become friends and begin to hang out after school, where Chie asks Souji if he has ever heard of the "Midnight Channel"—a channel one can view on their turned-off TV when they are alone at midnight during rainy weather. It is said that while staring at one's reflection on the screen, their soulmate will appear instead.

Believing it to be an urban legend, Souji, Chie, and Yosuke decide to tune in at the stroke of midnight, when they witness a classmate of theirs appear on the screen. When the same classmate ends up being the next victim in the serial murders, the three of them realize that the mysterious Midnight Channel is somehow involved. As the police struggle to find any leads, Souji and his new friends decide to investigate the mystery themselves, beginning a search that takes them not only across Inaba, but also into a mysterious parallel world beyond the TV.