Chakra Blades

A highly uniquely-designed trench knife, these blades are worn like brass knuckles, but each one has a sharpened zigzag "tooth" over each knuckle, and a blade coming out of one end. The knives are made from a special metal that can be infused through "chakra flow" with elemental chakra or Yin–Yang chakra to produce added effects.

Asuma Sarutobi couples these knives with his taijutsu skills to devastating effect, such that he can take out nine Otogakure ninja in a matter of seconds. When infused with wind-natured chakra, it can easily pierce through stone. The knives' damage and effect can also be maximised if the person has a better control of their chakra as seen with how Asuma was training Sora and Naruto Uzumaki in focusing their wind chakra into their kunai. After Asuma's death, the blades come into Shikamaru Nara's possession. When infused with his shadow chakra, it can immobilise anyone whose shadow it pierces.

Trivia

 * Naruto is seen using the chakra blades in the non-canon Naruto x UT OVA.