"DAN DA DAN" centers around a high school student named Momo Ayase, who possesses the unique ability to see and communicate with ghosts. This ability, inherited from her grandmother, often isolates her from her peers, as she struggles to balance her supernatural encounters with her ordinary life. The story begins when Momo encounters a mysterious boy named Okarun, who claims to be a ghost hunter. Despite his eccentric demeanor, Okarun reveals that he is searching for a powerful spirit known as the "Dan Da Dan," a malevolent entity tied to a series of unexplained deaths in their town.

As Momo and Okarun team up to investigate the Dan Da Dan, they uncover a deeper conspiracy involving ancient rituals, a secretive organization, and the lingering spirits of the deceased. The narrative explores themes of grief, redemption, and the blurred line between the living and the dead. Momo’s ability to see ghosts becomes both a burden and a tool, as she learns to harness her powers to protect those around her. Okarun, on the other hand, grapples with his own past and the reasons behind his relentless pursuit of the Dan Da Dan.

The series introduces a diverse cast of characters, including other students with supernatural abilities, vengeful spirits, and enigmatic figures tied to the town’s history. Each episode builds on the central mystery, revealing fragments of the Dan Da Dan’s origins and its connection to Momo’s family. The plot is driven by a mix of episodic ghost-hunting adventures and overarching storylines, creating a balance between self-contained episodes and long-term narrative progression.

As the stakes escalate, Momo and Okarun face increasingly dangerous spirits and moral dilemmas, testing their resolve and their growing bond. The series maintains a tone that blends supernatural horror with moments of humor and emotional depth, offering a multifaceted exploration of its characters and their struggles. By the end of the first season, the true nature of the Dan Da Dan is revealed, setting the stage for further developments in the ongoing battle between the living and the dead.