As with its predecessor, both series are known for their abundance of fan service in the form of panty shots and nudity.

[2] The mini-series follows 16-year-old Aika Sumeragi, who recently got her C-class license to be a salvager, a person who searches for treasure among the ruins of the Earth's cities which have been submerged following worldwide earthquakes.

However, one afternoon, she is invited by Eri Shinkai, the class president, to join her Treasure Hunting Club where they look for the coordinates hidden away in a tattoo on classmate Karen Minamino.

Aika gladly accepts, but during the trip some of her schoolmates and even their club advisor attack them in an effort to try to capture Karen.

They discover that there are aliens who use rope-like tendrils to probe the girls, knocking them out and harvesting their energy, or possessing them to do their bidding.