As a socially awkward college student, Hayeon lives a pretty boring life—except she can communicate with outer space. One day, she meets Ujun, an alien who is curious about human nature. When she rejects his request to "borrow" her body, he takes over the body of her crush! As Hayeon helps Ujun adjust to human life, their friendship blossoms into something more. However, their love story faces many obstacles, including an alien plotting to invade Earth. What will be the fate of these star-crossed lovers?