A virus is raging in an island city called Tasaka. It parasitizes in the human body and absorbs the nutrients absorbed by humans. It hatches and turns into a monster with countless wings wrapped around its body and giant eyeballs. People named it "Angel". The angel is as huge as an adult elephant and will attack humans indiscriminately. Its single impact is enough to destroy a building, and its feathers are as impenetrable as steel.
The city is divided into ten districts, ranked from one to ten according to the degree of development and importance. The administrator of each district is responsible for the safety of residents in each district.
The protagonist Ifino is the manager of District 1 and a university professor. He is in his thirties but still looks like a teenager. Iphinuo's right calf was broken during an angel's destruction, and he could only rely on a wheelchair to move around.
In order to prevent the virus from being brought out of the island, the managers sealed off the entire city with no entry or exit, and organized hundreds of heavily armed teams to patrol and protect the entire city continuously. Whenever angels are found, they will set fire to destroy them.
But people soon discovered that they simply could not afford the casualties and supplies required to destroy the angels.
At this time, the headquarters gave Iphinuo a mysterious task. Based on the genes extracted from the angels, the headquarters developed an artificial demon to deal with the angels, allowing Iphinuo to become the "breeder" of this demon. At the same time, the headquarters told Ifino that it would destroy him without hesitation after the disaster is over.
Concept: The good and evil sides of human nature