The large mecha behind the series premise are none other than a biomechanical organism known as Evangelion (or Eva). The pilots (after donning "plug suits") are inserted via an entry plug into the back of the Eva Unit. The interior of the cockpit contains basic controls, but the pilots also have a certian degree of mental connection to their Eva. Later in the series, the secrets the Evangelion Units hold become known.

Nearly every character in the series (a 26 episode series, at that) has a lot of emotional turmoil that they attempt to deal with. From uncaring fathers to mothers who commited suicide, the characters all have plenty that troubles their minds. In the ending of the series, there is a giant dive into the recesses of the human mind and what brings about such mental unstability.

After Evangelion came to an end on Japanese television, there was a huge debate over the ending. Some found the ending to be fulfilling and to be a very different turn for the series, where as that same turn outraged others. Regardless, three theatrical releases were created. Evangelion: Death, Evangelion: Rebirth, and End of Evangelion.