Σεζόν 1・Jiro Azuma is no average high schooler. A descendant of ninjas and trained in the ancient warrior art of the shinobi, Jiro is also able to talk with animals. After a mysterious encounter with an injured cat named Rago, Jiro discovers the feline is actually the legendary Black Star of Doom! Joined by the Bureau of Espionage, they fight off swarms of mononoke lying in wait to exploit Rago's powers.

Σεζόν 2・Beryl Gardenant, a swordmaster from the countryside, is settling into his new life as a special instructor for the Royal Order of Knights and the guardian of an orphan. A peaceful life is not in the cards, however, and Beryl is confronted with new obstacles. At the magic institute, in his hometown, at the kingdom's border, away in a foreign land... It's time for Beryl to face new battles.