Game is set on 4 years after the end of the previous game, Galaxy Angel Eternal Lovers.

In this sequel, due to the development of a method to cross-dimensions at the end of Galaxy Angel Eternal Lovers, a new dimension called NEUE was discovered, which is linked to EDEN through a space called ABSOLUTE, a central hub to which all dimensions are linked. This hub cannot be operated by most people however, and currently, the only person who can is the Moon Angel Troupe's Milfeulle Sakuraba. Since the operation of the hub involves opening gates between different dimensions, those with the ability to do so are called "gate keepers". The new Rune Angel Troupe features Emblem Frames from NEUE and is the successor to the now disbanded Moon Angel Troupe.

[From Wikipedia]