While playing the newly released MMORPG 'The World,' Minase Mai and Tomonari Kasumi collapse in the real world and are sent to the hospital after hearing a mysterious sound. Only Mai recovers, while her friend Kasumi slips into a mysterious coma. Mai is later approached by the creator of 'The World,' Tokuoka Junichiro, who unveils to her that, just like her friend, six other players across the country also collapsed while playing 'The World' and are now in mysterious comas. What exactly is 'The World,' what is this mysterious sound Mai keeps on hearing, and why are people slipping into comas from this game? Minase, Junichiro, and their acquaintances set off to get to the bottom of this problem before any further harm happens.