The Kusanagi-no-Tsurugi, also known as the Kusanagi Sword or Grass-Cutting Sword, is a legendary sword in Japanese mythology. According to folklore, it is one of the three sacred treasures of Japan, along with the mirror Yata no Kagami and the jewel Yasakani no Magatama. These treasures symbolize the legitimacy of the imperial family.

The Kusanagi Sword is said to have been discovered inside the body of an eight-headed serpent or dragon named Yamata no Orochi, which was slain by the storm god Susanoo. It is often depicted as a powerful and enchanted weapon.

In terms of its physical appearance, the specific details vary in different depictions and interpretations. However, it is generally portrayed as a longsword or a katana with a curved blade. The sword's name, Kusanagi-no-Tsurugi, translates to "Grass-Cutting Sword," indicating its legendary ability to cut through dense vegetation.

The Kusanagi Sword has significant cultural and mythological importance in Japan. It is closely associated with the Japanese imperial family and is regarded as a symbol of power and authority. The sword has become a part of Japanese folklore and has been referenced in various forms of media, including anime, manga, and video games.