30 years ago, a strange phenomena called a "spacequake" devastated the center of Eurasia, claiming the lives of at least 150 million people. Since then, smaller spacequakes plague the world on a irregular basis. Shidō Itsuka, an ordinary high schooler is recruited by his sister and comes across a mysterious girl at the ground zero. His mission is to stop the girl from causing the spacequakes. However, there is a catch: to seal a Spirit, he must make her fall in love with him.