Please note that this is the Narutopedia's article on the chokutō wielded by Sasuke Uchiha. If you are looking for the article on the sword wielded by Orochimaru then you should head to Sword of Kusanagi.
Sasuke Uchiha claimed that the chokutō he wields is a Sword of Kusanagi; it has a black scabbard and matching hilt (these are both blue in the anime), and is a larger size than a normal chokutō. Despite this, it has none of the natural specialities as the oneOrochimaru wields, such as the extension of the blade and the ability to cut through almost anything, both of which are natural attributes of the Kusanagi.
To compensate for this, Sasuke can channel his lightning chakra into the blade with chakra flow, which will increase its sharpness greatly through high frequency vibrations, as well as increasing its cutting range. This would allow Sasuke to cut through almost anything, as well as numb the target who has been pierced by this lightning blade. During the Fourth Shinobi World War, a reincarnatedItachi Uchiha while cooperating with his brother, temporarily wielded the blade to engage Kabuto Yakushi.
The Kusanagi no Tsurugi (草薙劍; Literally meaning "Grass-Mowing Sword") is one of the Three Imperial Regalia of Japan (三種の神器, Sanshu no Jingi), together with the Yata no Kagami (八咫鏡; Literally meaning "Eight Span Mirror") and the Yasakani no Magatama (八尺瓊曲玉; Literally meaning "Eight Shaku Curved Jewel").