Yokohama Station SF

In a future where Yokohama Station covers most of the island of Honshu, there are two ways of life--inside the station and outside. Life within the station is strictly controlled, and those who fail to follow the rules are expelled to the harsher world outside. When one of these exiles receives a temporary ticket to go into the station, he's also given a mission to find the leader of a group determined to free humanity--