Photo/IllutrationYoshimitsu’s Tanto (Yoshimitsu’s dagger), left, and the Aoe no Otachi (long sword of Aoe) are among blades on display at the Sanada Treasures Museum. (Yuki Kitazawa)

NAGANO--Legendary swords associated with feudal warlords of the Sanada clan are on display at a special exhibition at the Sanada Treasures Museum here.

“Sanada x Katana” (Sanada and swords) brings together about 30 blades, including ones apparently owned by Sanada Nobuyuki and his younger brother Yukimura (Nobushige) as well as others related to some of the crucial battles in Japan's history.

Historical materials detailing how the swords were kept are also on show.

Yoshimitsu’s Tanto (Yoshimitsu’s dagger) at the show is believed to have been presented by Tokugawa Ieyasu (1543-1616), founder of the Tokugawa Shogunate, to a son of Nobuyuki, inspired by Nobuyuki's loyalty.

During the decisive Battle of Sekigahara (1600), often considered the start of the shogunate, Nobuyuki fought alongside Ieyasu, the eastern army's chief commander, parting his ways from his father, Masayuki, and Yukimura.

When Nobuyuki offered his then-4-year-old second son, Nobumasa, as a hostage so he could live at Ieyasu’s Edo Castle, Ieyasu is believed to have drawn the dagger from his waist and given it to Nobumasa.

The 24.6 centimeter-blade was named after Yoshimitsu, a swordsmith in the Kamakura Period (1185-1333). It was kept firmly under lock and key in a “tansu” chest of drawers in a large room of Matsushiro Castle.

The Sanada clan ruled the Matsushiro Domain, present-day Nagano.

Also on display is Aoe no Otachi (long sword of Aoe), a “haito” sword worn at the waist, that is believed to have been used by Masayuki’s older brother, Nobutsuna, who was slain in the 1575 Battle of Nagashino.

Nicks on the 103.3 cm-long blade forged in the Muromachi Period (1336-1573) are seen as evidence it was wielded by Nobutsuna during the battle.

The Sanada clan referred to these old swords as “okoshimono” (precious things worn on the waist). They were used to show the social and family status of the domain lord and presented as gifts on key diplomatic occasions.

The items were distinguished from swords used as weapons and were placed in the hands of a “bugyo” magistrate specifically assigned for the job.

Ledgers for okoshimono and other historical materials can also be viewed at the exhibition.

“It's a first to have many swords associated with the Sanada clan gathered in one place,” said Izumi Mizobe, a researcher at the Matsushiro Cultural Artifacts Office. “We hope you enjoy the ambience of each piece, but we’d be happy if you also take an interest in how they were used and taken care of by the family of the ‘daimyo’ feudal lord.”

The exhibition runs until Sept. 23. The venue is closed on Tuesdays, in principle. Admission is 600 yen ($5.60) for adults.

Visit the museum’s official website at (https://www.sanadahoumotsukan.com/en/index.php).