No. 12

No. 12 is a robot worker that came under the control of Ms. Nagisa in Episode 13. Can only respond "Yes!" (also heard as ふぁい, Fu~ai) to every statement. Has a really weak design and will follow the command of a remote no matter who holds it.

It is considered to be an integral part of the submarine city that manages to "regulate the air-conditioned environment". As the name suggests, the "undersea city" is a city on the ocean floor, and it has the problem of having to adjust the air pressure inside to a high level (this is called a saturation diving specification) in order to resist the enormous water pressure outside. (LeMU, another undersea city, was crushed by water pressure about 50 years before this case.) Simply increasing nitrogen and oxygen may cause health problems, and "controlling internal air conditioning (atmospheric pressure)" is a more serious responsibility than one might think. Unlike the outside, which also functions as an aquarium, the central control room is not designed for long-term human survival (partly because the robots do most of the work). As a result, the director of the station turned white due to lack of oxygen, and the sound emitted by No. 12 was distorted.

In order to control No.12 and the other robots, it is necessary to command them with a transceiver-type terminal that adds administrator authority, which is usually managed by the director. However, during the bombing of the underwater city by the Juralians, the brainwashed Ms. Nagisa took it away from him and ordered him to stop the oxygen. Also, at this time, he responded to the request, "destroy all the other robots in this room!", it seems that the authority of the director is quite strong.