Kousuke Okano

A ninja must serve a lord, and Recca Hanabishi has sworn to serve the person who can defeat him in battle. But despite his martial prowess, penchant for traps, and his family's fireworks, his battles amount to little more than schoolyard brawls.

Brought up in the justice system, an orphan hiding her identity as a cold-blooded killer raids the streets of Tokyo, searching for freed criminals.

At the Ninjutsu Academy, Doi teaches young ninjas known as "Nintama." One day, he goes out for a battle against a ninja from the rival clan, but vanishes without a trace. The Nintamas worry for Doi's safety. At the same time, the Academy receives troubling news that their rivals at Dokutake Castle may be scheming something.