Centuries ago, an
extraterrestrial named Do Min-joon stranded on Earth during the Joseon Dynasty. Possessing extraordinary sensory powers and eternal youth, he has lived among humans for four hundred years, viewing them with cynical detachment. Now a university professor, Min-joon's bitter isolation is abruptly tested when vibrant, self-absorbed top Hallyu actress Cheon Song-yi moves into the luxury penthouse next door. Initially, Song-yi’s chaotic, demanding life—plagued by relentless media scrutiny and a declining career—irritates the stoic alien, who prefers quiet solitude. However, as Min-joon uses his supernatural abilities to repeatedly rescue her from bizarre accidents and malicious public scandals, an undeniable, protective bond forms between them.Complicating matters, Min-joon discovers a cosmic anomaly: within three months, the interstellar phenomenon that brought him to Earth will finally allow him to return home. As he prepares for departure, he realizes he is deeply in love with Song-yi, forcing him to grapple with the agonizing prospect of leaving her behind. Meanwhile, danger looms closer to home. Lee Jae-kyung, a psychopathic and wealthy corporate heir, targets Song-yi because she inadvertently possesses a flash drive containing evidence of his brutal crimes, including the
suspicious death of a fellow actress. Jae-kyung systematically eliminates anyone who stands in his way, turning his ruthless sights on Song-yi and framing her for drug use and erratic behavior to ruin her completely.Min-joon uses his otherworldly powers to shield Song-yi from physical danger and media destruction, frequently risking exposure to the public. As Song-yi uncovers the truth about his alien identity, her love only deepens, accepting him despite his impending departure. The dramatic tension peaks when Jae-kyung abducts Song-yi and stages a fatal trap, pushing Min-joon to break his strict rule of never using his powers for personal intervention. He rescues her in a breathtaking display of abilities, ultimately exposing Jae-kyung’s heinous crimes and sending the villain to prison. Yet, the heartbreak of the impending cosmic separation remains inevitable. On the night of his departure, Min-joon experiences a wormhole phenomenon that pulls him away from Earth, leaving Song-yi utterly devastated. Years pass, and Song-yi grieves profoundly, pouring her heartache into her acting career while refusing to move on. Miraculously, through tears in the fabric of space-time, Min-joon figures out a way to bend the rules, mastering teleportation to briefly visit Earth. Although his appearances are initially erratic and fleeting—vanishing without warning—their profound love bridges the galactic divide. Ultimately, Min-joon finds a way to spend more sustained, reliable time on Earth with Song-yi, blending his alien existence with her human world to achieve a hard-won, timeless happily ever after.