In the central city of Tanagra, which is ruled by the enormous computer Jupiter, Riki was held captive in the Eos Tower, the residential area of the privileged class. He was kept as a pet by one of the most elite artificial beings, a blonde individual known as Iason Mink. Despite having his freedom and dignity stripped away and undergoing inappropriate training, Riki refused to be tamed and resisted those around him.

Then, one day, while Riki stood in front of the heavily guarded entrance gate of Eos, a door that should never have opened suddenly did. In this unprecedented escape event initiated by Riki, Iason was faced with a dilemma...