Princess Kaguya Takenouchi is rebellious and defiant, making her an unsuitable heir to the Silver Court of the Moon. However, when evil usurpers attack her people, she must take action and protect the royal line.

When the Empress falls ill during a series of terrorist attacks, Kaguya decides to do the right thing for her people. Desperate in the Contaminated World and hunted by ruthless Ume assassins, she tries to find a way to honor her promise to her mother and return to the Moon.

Together with her Imperial Guard student, Mikuni, she travels to a base that is supposed to offer salvation, only to find something very different inside…