Thirty years ago, over a hundred million people perished in an unprecedented catastrophe dubbed a "spatial quake." Since that event, humanity has developed countermeasures to lessen the impact of future disasters, including instantaneous evacuation protocols and the immediate reconstruction of damaged structures. Currently, 16-year-old Shidou Itsuka lives alone with his sister, Kotori. One day, he is caught in a spatial quake despite prior warnings. He miraculously survives the blast and encounters a mysterious girl in its aftermath, whom he soon identifies as a "Spirit"—a supernatural entity responsible for causing these spatial quakes. By coincidence, he also learns of the "Anti-Spirit Team," a specialized military unit charged with destroying these Spirits through brute force. Before these revelations can fully sink in, Shidou is recruited by Ratatoskr, an organization committed to peacefully mitigating the threat posed by Spirits—with his sister serving as its commander. As Ratatoskr's new weapon, Shidou must neutralize the Spirits' powers to stop them from causing further destruction. His method of engagement: going on dates with them and sealing the deal with a passionate kiss.