In a world where an AI programme allows people to communicate with their deceased loved ones, a flight attendant and a mother question the meaning of reality and humanity.

Min-sang, a meticulous planner and tidy single man, is frustrated daily by his tenant, Jin-young, a veterinarian who turns his newly mortgaged building into a mess. During another quarrelsome day…

Ji-woo, an outcast at a prestigious private school, meets Hak-sung, the school janitor who is actually a mathematical genius who defected from North Korea.