Miyu, a vampire girl, acts as a guardian, sending stray demons known as Shinma back to the darkness while publicly posing as a high school student.

The year is Universal Century 0079. Oliver May is a technical officer in the Zeon 603rd Technical Evaluation Unit , in charge of testing new military technology. Stationed in the Jotunheim, a civilian transport ship that was converted into military use, Oliver must head into battle and experience the One Year War, only this time from the perspective of a weapon tester who struggles to make an impact on an evolving war during changing times.

The Sacred Book of the land of Eija has been rediscovered and with it the legends of a mysterious and all powerful ship. Now Princess Crystal of Megaronia has set forth on a quest to recover the ship and its ultimate weaponry. All that stands between her and total domination of the world is a small group of piratical misfits. Swords, sorcery and technology blend to form a mesmerizing tale of Good vs. Evil in Ellcia.