In Okinawa, Kakazu Kio, a typical high school freshman, encounters a girl with feline features named Elis, who asserts her extraterrestrial identity during a family memorial event. As fanatical alien devotees and a covert government organization give chase to Elis, Kio's childhood friend Manami, aspiring to join the CIA like her father, seizes Elis. Now, Kio must shield Elis from all threats that loom around them.