DAN DA DAN follows Momo, a high school girl from a family of spirit mediums, and her classmate Okarun, an occult freak. The two of them start talking after Momo rescues Okarun from getting bullied. However, an argument ensues between them – Momo believes in ghosts but denies aliens, and Okarun believes in aliens but denies ghosts. To make the mutual deniers believe in each other, Momo goes to an abandoned hospital known for its UFO sightings, and Okarun goes to a tunnel that is said to be haunted. In each place, they encounter overwhelming paranormal activity that transcends comprehension. Amid these predicaments, Momo awakens her hidden power and Okarun gains the power of a curse to challenge the paranormal forces! Their fateful love begins as well!?

The story of the occult battle and adolescence starts!