Year 2115, KANSAI district of Japan. The kids are prohibited from playing outside because of some serious air pollution. The outside world and nature doesn't really exist anymore. So the kids born in this era don't know what the real outside world is like.
So for the sake of these kids, an amusement facility was built. Its called Gocco Studio Japan. The studio reproduces a hologram version of the outside world and allows the kids to play games such as Gocco, a 100 year old game.
This is the story of kids playing inside a studio, making friends, helping each other out, finding love, betrayal, getting wrapped up in strange events and growing up.