Chakra

Chakra is the thing that is necessary for a user to use jutsu. It is an invisible energy that consists of the physical and spiritual energy. It is present in every living being in Naruto. It is stated that a user who uses up all their chakra or loses it all is at risk of dying if it is not replenished. The tailed beasts in Naruto are stated to have the highest quantity of chakra.

Chakra originated from the chakra fruit that the god tree produced. Kaguya Ōtsutsuki ate the fruit becoming the first person in the Naruto world to wield chakra.