Reeling from her recent breakup, Momo Ayase, a popular high schooler, shows kindness to her socially awkward schoolmate, Ken Takakura, by standing up to his bullies. Takakura misunderstands her intentions, believing he has made a new friend who shares his obsession with aliens and UFOs. However, Momo's own eccentric occult beliefs lie in the supernatural realm; she thinks aliens do not exist. A rivalry quickly brews as each becomes determined to prove the other wrong.

Despite their initial clash over their opposing beliefs, Momo and Takakura form an unexpected but intimate friendship, a bond forged in a series of supernatural battles and bizarre encounters with urban legends and paranormal entities. As both develop unique superhuman abilities, they learn to supplement each other's weaknesses, leading them to wonder if their newfound partnership may be about more than just survival.