Momo Ayase, a high school student who recently ended a relationship, shows kindness to her classmate Ken Takakura by defending him from bullies. Ken misinterprets her actions, thinking they've become friends who share his interest in extraterrestrial life. However, Momo's own fascination lies in the occult, and she believes aliens are not real.
Momo and Ken develop a close bond as they engage in a series of supernatural battles against urban legends and paranormal entities. As they acquire unique abilities, they learn to complement each other's weaknesses, leading to questions about the nature of their relationship.