On her way home, Sun-jung discovers that the earbuds she picked up on the subway are actually part of a robot from the future. The robot reveals to Sun-jung that her daughter will become a key figure in an anti-technology movement in the future, and threatens her to make her daughter use a smartphone in order to raise her as an ordinary child.

A talented martial artist who can't walk past a person in need unites with a probation officer to fight and prevent crime as a martial arts officer.