Kashu

The Kashū was a sword that once belonged to Baroque Works agent Mr. 11. After his loss in a sword duel with Tashigi of the Marines, she claimed the sword for herself. It is one of the 50 Ryō Wazamono Grade Swords.

As the Shigure the Kashū has a four-petal-shaped tsuba though those petals are round not tapered.

Abilities
Nothing is known what the Kashū is capable of, since Tashigi wasn't shown fighting with it.

Trivia

 * Though using the Kashū in the manga from Chapter 158 on, Tashigi never used this katana in the TV show since she still carries the Shigure in all of her appearances.
 * The Kashū is only to be seen and mentioned by dialogue in Episode 79. But there it has a common round tsuba.