A tantō (短刀) is simply a small katana. Several chūnin, medical-nin, and shinobi of Konohagakure wear them strapped to their lower backs when going into battle. The version Root uses is straight and double-edged with no tip, meant only for cutting and defence. They carry the tantō vertically on the back, specifically behind the shoulder; Sai is one of the notable ones that uses the tantō, which he carries on his back behind the right shoulder. Sakumo — and Kakashi Hatake after inheriting it — carried a special tantō, known as the White Light Chakra Sabre. Gamabunta and Gamakichi also carry these, albeit gigantic versions that fit their size.