Nobody knows where they came from. They parasitize in human beings, take control of them and change their bodies into hideous monsters (Necro-borg). The Necro-borg fight each other until the other dies. Where did they come from? To what end? Yuji and Kaoru, whom both have dark secrets within themselves, get caught up in the horrific battles of Necro-borg. What will their fate be?

Set towards the end of World War II, Nomura (Masatoshi Nagase) is a writer who is in despair. A woman works in bar and is a former prostitute. Many years ago, her father sold her to a brothel due to the family's severe financial hardships. The writer and the woman then agree to live as husband and wife until the war ends. The woman doesn't feel sexual pleasures due to her past, while the man lusts for the woman's body. Meanwhile, Ohira (Jun Murakami) fought for Japan in China. He participated in unconscionable acts against civilians in the name of war. He returns to Japan with only one arm. Ohira then begins to prey on innocent women.

Three girls - Miwa, an introvert who's best friend is her turtle, Saori, a rich girl from a celebrity family, and Koyuzu, a member of a revenge agency - wind up in a complex rivalry with one another.