In Shibuya, Tokyo. It has been announced that an anonymous serial killer is on the loose, everyone is instructed to hide in a safety shelter, far away from Shibuya and to never leave until instructed. Unfortunately 20 teenagers weren't informed of the situation, now questioning why everyone in the city is nowhere to be seen. These 20 teenagers come from different units and bands, most of them knowing each other, now panicking they can't go back to their sekais they try to uncover the reason they were left lone in the abandoned city while trying to survive. As for the vocaloids in the sekais, they are nowhere to be found.. How do you think these units survive? Will they ever survive? (Side note: Some characters may be out of character, and I do not own the characters in this book, I only own the plot.)