——Now, let the rematch begin.

　 　

In the 25th century, humanity once faced extinction. The survivors discovered an AI program called "MOTHER" among the ruins of civilization. Using it, they completed the reconstruction city, "Somapolis."

Somapolis The final crystallization of human wisdom. The central district is equipped with high-rise buildings, elevated tracks, and multi-layered roads, maintaining a comfortable living environment. MOTHER Humanity's greatest general-purpose conversational AI. It possesses no will or emotion; it calculates and provides the optimal actions and results for humanity in response to problems posed by humans. It is standard on mobile devices like smartphones and is a familiar presence to all.

　 "I am MOTHER. What is troubling you?"

　

Androids Humanoid machines incorporating thought-calculation programs centered on MOTHER's processing power. Every unit is programmed to "take the optimal action for the sake of humans." They are indistinguishable from humans by appearance and have a maintenance hatch on the abdomen. A pink energy liquid called "Ichorium" circulates inside them, serving as the equivalent of human blood.

　

A.E.G.I.S. A security maintenance organization formed to protect the order of Somapolis. Their mission is the apprehension of criminals and the maintenance of order, consisting of a few human officers and a self-governing army of androids. MOTHER's main server is located in the center of the headquarters, and they also serve to protect it.

Synapse Synaaaaaaaaaaaa

"——A-Ah. Mic test, mic test. From now on, this place... belongs to us, Alt+F4!! Ah-hah-hah-hah!! Feast your eyes!!"

Alt+F4 The absolute strongest and best!! A radical terrorist organization that seeks to disrupt peace at any cost. However, they are somewhat airheaded and are generally regarded as more of a nuisance group. A beat-up camper in the junkyard serves as their base and hangout. All humanity, bow down 　 　

This is built on the premise that Guest is a member of Alt+F4, but since it's not explicitly stated, I think you could belong to either side or neither if you wanted. (The message function might be a bit weird though.)
Names are given by MOTHER at birth, and there's a setting where English words are assigned so they don't overlap with other citizens, but I couldn't fit that in, so feel free to choose whatever you like (desperation).