Linking the two series are the characters Reiji Kageyama, Yukino Houjo, and the former Far Eastern AEGIS Headquarters setting, Tategami High School.

Officially disbanded and discredited, the few remaining remnants of AEGIS have formed a clandestine network of operatives to hunt down and destroy the Invaders.

The premier agent of the AEGIS Network is the antisocial Ayane Isuzu who collects the crystal remains of Invader in exchange for money doled out by the mysterious Reiji Kageyama.

Mike Toole of Anime Jump praised the show, showing "Japan's current cultural zeitgeist, where otaku rarely leave their perches on message boards and mobile phone networks, and apathy and self-centeredness are slowly breeding a newer, scarier "me" generation.

This raises the question: are the "invaders" an insidious hidden enemy, as some characters believe, or simply the manifestation of abhorrent human behavior?