The year 2121. Japan's population has dropped below ten million due to declining birth rates. To save the nation from collapse, two aggressive girls are sent back in time to the present day—2021. They are the descendants of Kurea Hasumi and Tsubasa Hachino. One day, as a young man is masturbating using adult VR, the two women suddenly appear before him. Laid flat on his back, staring up at the ceiling, his fate is sealed. What will become of him—and of Japan's future?