Bio Defense ~A City Built in a World That Has Ended~

The world suddenly met its end. It appeared suddenly, attacking people who were living peaceful, everyday lives. It took up residence in the former daily lives of people, emitting a foul odor and presenting a hideous appearance.

It spread from person to person, with infected people attacking those who were not yet infected, and the damage spread at an alarming rate.

There is currently no way to counter it.

Peaceful daily life quickly turned into an extraordinary world, and the remaining people gathered and formed several cities in Shikoku, seeking a way to strike back and trace the roots of the infection.

However, the infected also evolved, making the difficult situation even worse. Furthermore, in the midst of this chaos, there were those who schemed to take advantage of others for their own gain, those who acted on their desires without reason, and those who sought to exploit the situation for their own benefit, baring their fangs and driving the panic to new heights of confusion.

Kanata, an ordinary high school student, was caught up in the panic and took refuge in one of the cities. Together with his friends, he joined the city's defence force and became part of the 11th Division. He spent his days fighting against the infected, external plunderers, and getting caught up in the schemes of the different cities, while meeting and parting ways with various people.

And then, he eventually arrived at a certain truth.

It was something that forced him to make a big choice.