DAN DA DAN follows Momo, a high school girl from a family of spirit mediums, and her classmate Okarun, an occult geek. 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. Hoping to change the other's mind, each of them agree that Momo will go to an abandoned hospital known for its UFO sightings, and Okarun will go to a tunnel that is said to be haunted. In each place, they encounter overwhelming paranormal entities that defy comprehension. In a moment of peril, Momo awakens her hidden power and Okarun gains the power of a curse to challenge the paranormal entities! Could this be the start of a fateful romance as well!? Now begins a new story of occult battles and adolescence!