In the "Naruto" anime and manga series, Sasuke Uchiha, one of the main characters, wields a sword named Kusanagi. Kusanagi holds significance in the story due to the following reasons:

1. Connection to Orochimaru: Kusanagi originally belonged to Orochimaru, a powerful and sinister character within the series. Orochimaru is known for his extensive knowledge of forbidden techniques and his quest for immortality. The sword represents the link between Orochimaru and Sasuke, as Sasuke acquires it during his association with Orochimaru.
2. Chakra-Conductive Properties: Kusanagi possesses unique properties that allow it to conduct chakra, the energy used for various techniques in the Naruto universe. Sasuke, being a skilled user of lightning-based techniques, is able to infuse his chakra into the sword, enhancing its cutting power and enabling him to perform lightning-based attacks.
3. Versatile Weapon: Kusanagi is a versatile weapon that can be used for various purposes. It has a long blade, allowing for both slashing and thrusting attacks. The blade is sharp and durable, making it effective in combat.
4. Symbol of Sasuke's Power: As one of Sasuke's primary weapons, Kusanagi symbolizes his strength, skill, and determination. It is associated with his progression as a warrior and his pursuit of power and revenge.

It's important to note that the specifics of Kusanagi's abilities and significance may vary slightly between different adaptations and interpretations of the Naruto series.