Apollo, a robot designed to appear human, lives on Planet Abel where humans and robots coexist. Aboard a transport vessel, he discovers a mysterious stowaway attempting to invade the planet. This stowaway possesses a memory chip containing the advanced camouflage software "Cipher" OS. Apollo removes the Cipher chip out of curiosity, unaware of the repercussions. After acquiring the chip, he develops increasingly erratic behavior.

His actions capture the attention of Mikaru, a human with a robotic appearance, though she does not initially recognize the chip's role in Apollo's condition. Together, they investigate the nature of Cipher, uncovering secrets bridging past, present, and future. Their collaboration focuses on unraveling the OS's origins, capabilities, and true purpose. This journey requires them to face challenges testing their conceptions of identity and technology within their world.