In the year 2043, the virtual reality MMORPG Infinite Dendrogram is released, featuring the ability to perfectly simulate players’ five senses. Nearly two years later, Reiji Mukudori enters the world of Infinite Dendrogram and assumes the name "Ray Starling", and upon his arrival, he is joined by his more experienced brother Shuu and his Embryo companion Nemesis. As Ray explores the world of Infinite Dendrogram, he learns to make a life for himself there and meets different kinds of friends and foes.
