Cross†Channel

Gunjo Academy is a facility designed to gather and isolate those students who got a high score on an adaptation exam (Scoring high on this exam indicates that the student is less likely to be able to be adapted to the society) mandated by the government.

After a failed summer vacation with other members of the school's broadcasting club, Kurosu Taichi and some of the other club members return to the city, only to find that all living creatures within it except for the club members have completely vanished. In order to confirm the status of the outside world, Taichi decides to gather other club members to help Miyasumi Misato, the president of the broadcasting club, who is trying to set up a broadcasting antenna to contact any possible survivors.

(Source: Wikipedia)