Shusui is one of the 21 O Wazamono grade swords and was once wielded by the legendary samurai Ryuma. It is considered the national treasure of the Wano Country. After his death, the katana was buried with Ryuma, until his grave was robbed by Moriah's crew. Ryuma appeared as a zombie on Thriller Bark, who had been given Brook's shadow. After his defeat, Ryuma bequeathed the sword to Roronoa Zoro, and said he was satisfied with Zoro as the sword's master. The sword then replaced Zoro's Yubashiri which was destroyed at Enies Lobby.