Corporobos appear as robots that are divided by worker ranks. There are six ranks total, with two ranks sharing nearly identical designs.
MDL-WKR robots appear as small, blue worker robots with a square shaped build, yellow eyes without pupils, pincer-like hands and a red tie. They have an antenna on top of them and a wind turbine on their back. MDL-CH appears nearly identical, aside that it is yellow in color.
MDL-AM robots appear as red, tall, slender robots with a long, stubby head and appear to have no facial features. They appear to have a blue tie as well. Their body appears as flexible and jointless. MDL-DMs appear as a blue variant.
MDL-GM robots appear as green robots with large builds with a red tie, with short, broad heads with an antenna on top of it. It has a blue visor in place of visible eyes. Haru Okumura's Fiance appears as this model, but is colored in white and pink.
MDL-ED is a much larger version of the MDL-GM variant that is black in color with a pair of glowing red eyes and a mustache on its face.
Corporobos are cognitions that appear in Okumura's Palace that symbolize Kunikazu Okumura's viewing of his workers as dispensable labor. As he has no regard to his workers and forces them to work overtime and he is constantly looking for the biggest business ventures possible, these robots are devoid of any personality and work themselves to death in his spaceport Palace. If a robot collapses and breaks due to overwork, it is instantly sent to be destroyed and transformed into the spaceport's fuel.
They act as the unique obstacles in Okumura's Palace and are his main line of defense, as he deploys them throughout the Palace, in which the high ranking robots hold the keycards required to reach the factory area which must be defeated to progress. They are only weak against two types of elements but resist everything else excluding Almighty, including Physical and Gun attacks. As they are cognitions, they cannot be recruited or negotiated with in any form or way.
Eventually at the climax of Okumura's heist, Shadow Okumura deploys the Corporobos against the Phantom Thieves of Hearts after Morgana bypasses and deactivates his trap, sending out every rank of Corporobo in his disposal. After the previous five ranks are defeated, he deploys his right hand man, the Execurobo MDL-ED. However, it too was no match for the party, leaving Shadow Okumura open and vulnerable, leaving him defeated easily.
All of the Corporobos now no longer resist Gun skills and can be inflicted with ailments for Technical damage, including the Execurobo. However, they are still all immune to Brainwash, Despair, Fear, and Rage, as well as instant-death abilities.
When Okumura orders them to fight, he will automatically restore the entire wave of robots if they are not defeated within two turns, and he can cast buffs on them, particularly Rakukaja, to make disposing of them all at once much more difficult.
Okumura will command the groups of robots to attack one party member exclusively, until either the target is defeated or the robots execute one full wave of attacks without knocking down their target, whereupon Okumura will become exasperated and order the robots to switch targets. Okumura will also order the robots to switch targets if the targeted party member is undetectable for some reason, usually when he's being removed from the party using Hifumi Togo's Koma Sabaki ability.
The Execurobo will not be ordered by Okumura in this way, and can attack any party member at will, though it has a strong preference to attack Haru Okumura if she is in the battle.