Park Il-soon (Jung Ji-hoon) in a mental hospital is a compulsive adaptive youth who believes he can steal other people's abilities and thoughts. As long as he wears a mask, others can't find him. He always thinks he can steal anything he can think of. One day, the new girl Cha Young-jun (Lim Soo-jung) becomes his new target. Il-soon finds that Young-jun never eats. Her lunch box is full of batteries. Young-jun calls herself a robot. She listens to the radio and sometimes talks to the lights and vending machines. Il-soon becomes good friends with the girl who claims to be a robot. When she is unhappy, he steals her heart and falls in love with her. Young-jun tells Il-soon that robots cannot fall in love, and Il-soon says to Young-jun, "It doesn't matter if you are a robot." Young-jun's refusal to eat has reached a point of life-threatening danger, and Il-soon begins to try every possible means.