Yamato Koichi, a member of the Earth Defense Force, a secret organization that protects Japan from extraterrestrial lifeforms, believes that capturing the extraterrestrial lifeforms will lead to peace in the country.

One day, Koichi meets a woman from the Extraterrestrial Life Force. She says that her homeland was destroyed and she came to Earth, and asks Koichi a question.

"What do you want to protect Japan from?"

This encounter leads Koichi to face the existence of unreasonable evil that nests within this country that cannot be punished by law.