TV-MA | | Action
A coup in North Korea forces an agent to defect to South with unconscious "Number One". While operatives from North hunt for both of them, the agent has to work with South Koreans to stop the nuclear war.
The shared name of the two main characters, Chul-woo, is a homophone for 'Steel Rain' in Korean hanja - 'chul' can stand for 'steel' or 'iron', while 'woo' can mean 'rain' or 'rainfall'.
If anything happens to him, there will definitely be war!
Kwak Chul-woo: Okay.
In the theatrical version, the title card is shown in Korean but in the Netflix version the title card is shown in English.