Far Side of the Moon

This is the setting of CCC.
If one thinks of the Moon as being perfectly divided into two, the side facing the Earth is the Near Side, and the opposite side, which cannot be observed from Earth, is the Far Side.
Fate/EXTRA takes place on the Near Side, and the player progresses from the first layer to the seventh layer, and finally on to the Moon Cell‘s core. CCC takes place on the Far Side (no layers though), and the player similarly aims to reach the Moon Cell‘s core. Although the path is different, the goal is the same; Moon Cell‘s core.
The Far Side of the Moon is the place where Moon Cell keeps information and data that it has judged to be unnecessary; it’s essentially a dumping ground.
It’s an imaginary number space that swallows up all data categorized as malicious information, which is information/data that could only ever prove harmful to mankind or other life forms.
The Far Side of the Moon is a strictly off-limits area, and even the “eye” of Moon Cell‘s core is forbidden from entering.
All data that finds its way to the Far Side of the Moon is swallowed by humanity’s evil nature, and is eventually deprived of all meaning.
The Far Side of the Moon can be said to be the result of Moon Cell stashing away polluted information and data. This ocean of polluted data increases in size as Moon Cell continues to make its observations.
The illustration that Leo excitedly prepares for the player is extremely difficult to understand. Despite Leo complaining that Julius’ briefing was inefficient because it was too “Visual Kei,” Leo actually likes Gothic themed stuff quite a bit.

Fate/EXTRA Material: Encyclopedia of Fate/EXTRA

This refers not to the side of the Moon that you cannot see from the Earth, but to the other side of the Moon Cell’s internal structure.
The inner workings of the Moon Cell are divided into the Near Side and the Far Side, top and bottom, each in the shape of a half-moon.
The Far Side of the Moon is somewhat analogous to a giant “hell” that lies beneath the Earth’s crust.
Because the Moon Cell trashes information that it cannot understand, as well as unneeded divergences in human history, to its Far Side, that “side” of the Moon is a pool of chaos where innumerable curses and delusions flourish.

Fate/EXTELLA material: Encyclopedia of Fate EXTELLA