Saeko Matsuda

Set in a virtual simulation of Shibuya, Tokyo which is regulated by an entity named Piece which does not allow inhabitants to live, the series focuses on a fifteen-year-old boy named Tsuyoshi who seeks to find both his lost memories and a way to escape Shibuya. To maintain control, Piece locks "kills" those who do not operate within the proper confines of the world, which results in their being reset and inserted back into the city with a new name and identity and without their previous memories.

When a tragedy befalls their fellow students on graduation day, three pupils of the Hayate Way's Ninja Academy must take on the Jakanja — a clan of evil space warriors. But they can't do it alone. Can they find the help they need? And can the young warriors act swiftly enough to defeat the Jakanja before they destroy the known universe?