What is the Fuuma Ninja (Sagami Ranpa)?

The Rappa—a legendary group of ninja.
Based in Odawara and Hakone, their leader inherited the name Fūma Kotarō for generations.
They excelled in specialized horseback tactics, stealth operations, and disrupting enemy lines.

Recognized for their exceptional abilities, they served only the Odawara Hōjō clan for five generations, starting with their discovery by the first lord, Hōjō Sōun.

Although they appear in historical texts such as the Kōyō Gunkan, Hōjō Godaiki, and Kanhasshū Kosenroku, much of their true history remains shrouded in mystery.