In a world bound by invisible "sequences", the fate of mankind, social class, and even the survival of civilization all depend on climbing the sequence. The bottom-level cleaner "Zero", a weirdo who doesn't care about anything but does everything to the extreme, activates the legendary "initial sequence" in an accident and becomes the only "order breaker". He is not motivated by power or desire, but sees "climbing the ladder" as a "task" that must be completed perfectly. His journey, starting from a forgotten corner, will eventually shake the foundation of the entire civilization, reveal the ultimate truth behind the sequence about the survival or destruction of the universe, and make a final judgment on the fate of the entire world with his unique, emotionless logic.
