真紅の焔真田忍法帳（Kurenai no Homura Sanada Ninpou Chou）

Fourteen years have passed since the Battle of Sekigahara split Japan in two.

Now firmly in control, the Tokugawa shogunate is scheming to eliminate the Toyotomi clan, a long-standing thorn in its side. In response, the Toyotomi clan has decided to confront the Tokugawa head-on, using Osaka Castle as their stronghold. Calls for support were sent to daimyo throughout the nation. Yet not only did the majority of lords refuse the call—even those who once owed the Toyotomi their lives turned their backs. But some still answered the call.

One of these brave warriors was Nobushige Sanada.

During the Battle of Sekigahara, Nobushige Sanada, the second son of the Sanada family, fought alongside his father, Masayuki Sanada. They supported Mitsunari Ishida against the Tokugawa clan. As punishment, he was sentenced to permanent house arrest at Mt. Kudo in the Kii Province.

Those who follow Nobushige when he escapes Mt. Kudo and heads to Osaka Castle are none other than the ten ninjas who serve him. Their members include former samurai once loyal to the Sanada, ninjas who continued to work for the Sanada after their exile, warriors who gathered under the Sanada name to fight the Tokugawa, and even those who came to challenge Nobushige and the Sanada ninjas in battle.

These ninjas would later be known as the Sanada Ten Braves under Nobushige's command.

Standing in their way are the Ura Yagyu, a group comprised of assassins who have carried out many killings under orders from the shogunate, mysterious swordsmen, and mighty warriors.

This is the final chapter of the Warring States period. It is a tale of the bonds and way of life shared by Nobushige Sanada and the Ten Braves who gather at Osaka Castle.

[From Idea Factory International]