Dan Da Dan follows the strange and exciting adventures of Momo Ayase, a high school girl who believes in ghosts but dismisses aliens, and Ken Takakura (Okarun), a boy who is the opposite—obsessed with aliens but doesn’t believe in ghosts. Their lives take a wild turn when they encounter both entities and get entangled in a bizarre world filled with supernatural beings, aliens, and curses. Together, they must confront these otherworldly forces while navigating their unusual relationship and personal growth.

The story blends action, supernatural elements, and humor with unexpected emotional depth, as the duo faces escalating dangers and learns more about each other.