At some unknown time, the entire world was suddenly attacked by an unknown virus and almost completely destroyed.
But only children under the age of 13 were not infected by the virus and survived.
However, these children are ruled by vampires who emerge from the underground and are raised as livestock to provide blood.
The protagonists of the story, Hyakuya Yuichiro and Hyakuya Michael, were among the captured orphans. Faced with the unbearable fate, they did not give in and began to plan escape and revenge. However, Felina's return also put a layer of film on Yuichiro Hyakuya's revenge that is difficult to break.
Purpose: exist for readers