In a South Korean Mental Institute, two patients fall in love. Young-goon thinks she is a cyborg who requires electricity instead of food. IL-sun is a klepto who thinks he will shrink into a dot unless he brushes his teeth.
IL tricks Young into eating with a lie about a "rice-megatron". Young-goon then interprets a dream she has and believes that she is a nuclear bomb that needs to be detonated with a lightning bolt. Young and IL go out into a thunderstorm with a lightning rod to catch a lightning bolt but IL has secretly insulated it with a wine cork. When Young expresses concern that she will not detonate, IL says "Give up hope and cheer up".
The two survive the night and the sun rises revealing a beautiful rainbow.
Thanks Don P!