Momo

Momo is one of the companion robots in Walled City 99 that has evolved to act like a human.

Momo wears a summer green coat with a flamingo and green leaves painted on it. He wears a Chinese straw hat. Instead of a face, he has a screen with a rainbow background and a black face. -_-

Since the extinction of humanity, robots have come up with their own language, they speak it, but this language has two types.

All the robots are in the so-called "Vault"—Walled City 99. It was built by humans when the entire world outside was overrun by the plague, but it didn't help. Those who controlled it simply abandoned it, sealing the cement shell that blocked the sky, leaving the humans trapped forever. The humans died out, and the robots that had previously served them as cleaners evolved.

Momo himself is an outsider.
The Outsiders are a group of robots who believe that it is possible to leave this shelter or open the hermetic shell that closes off the real sky.

Momo has friends: Clementine, Doc, Zbalthazar—also outsiders. Momo kept notebooks with them, chronicling their success in finding a way out.

There are two sectors in Walled city 99:

Midtown is the upper and wealthy part of the city that looks free, but it is under the strict control of the guards (Robot police officers)

The slums are the lowest part of the city, but they're very large. Despite their size, there's only a small, safe patch of ground, with the rest overrun by Zurks.

Zurks are garbage-eating bacteria that have evolved to eat everything (even robots).

Unfortunately, all his other friends (Only Outsiders) went their own way, but remained alive:

Doc went outside the slums to test the weapon against the Zurks.

Clementine has reached midtown, but she can't get out.

Zbalthazar made his way through the sewers (The most dangerous place) into a huge room, settled there with others and meditated there.

Doc has a son, Seamus, who thinks his father is dead and is deeply depressed.