Asahi’s life in reality ended simultaneously, when she died playing “Union”, a world-renowned online RPG. The members of “Subaru” went separate ways when "Union" shut down due to Asahi's death. Six years later, Haruto logs onto a renewed version of "Re'Union" and reunites with Asahi who had died. Is she an electronic ghost? The "promise" the childhood friends made will unfold within the game.