The protagonist Zero is forced to find the legendary "original emotional core" in order to save the pet cat.
Cooperate with the information dealer Messiah, sneak into the upper city from the lower city, and get acquainted with Lilith, the daughter of the ruler.
During the mission, Zero discovered that he was the ruler - the biological son of the chief adjuster and a failed experiment, and that the entire world was built on a huge lie.
Zero refused to be his father's heir and chose to release his emotions, detonating the "resonance core" that maintains world order.
The old order collapses and the world falls into chaos but regains "emotional freedom." The protagonist regains his identity and humanity, and faces an uncertain future with his companions.
