Year 20xx. In a high-tech future, where people are divided into categories according to their birthstone, there are two important things: Box, the immense virtual reality that manages the data of the world population, and Logiste, a fierce dance competition, sometimes even dangerous, whose champions are considered real stars. To Kokoro Koyomi, however, all this is precluded because of her strict father, who forbids her to even talk about it. One day, she secretly gains access to Box, but remains stuck in the virtual reality because of a bug.

(from mangaupdates)