Amaterasu is the highest Fire Style ninjutsu, a dōjutsu available to the possessor of the Mangekyō Sharingan. Embodying the "Material World and Light," it serves as the opposite of Tsukuyomi. The technique instantly generates black flames at the point the user is looking at, making evasion practically impossible; however, a sufficiently fast opponent can avoid the attack or intercept the flames after activation. This fire, called the "flames of the underworld" and compared in heat to the sun, incinerates any matter — including ordinary fire — until only ash remains.
Amaterasu's flames cannot be extinguished with water or blown out; they continue to burn until the target is completely destroyed, and only the creator himself can dispel them. However, the burning is not always instantaneous: under normal flow, the flames spread slowly, allowing the victim to discard burning clothing or even remove the affected body part. One can defend by erecting a barrier that separates from the fire — for example, the chakra cloak of a first-version jinchūriki or sand. The flames are also vulnerable to absorption through the Rinnegan, to certain space-time techniques, and to the power of the Ten-Tails' Jinchūriki.
Using the technique causes severe strain, usually accompanied by bleeding from the eyes. Hand seals are typically not required, though Sasuke Uchiha once used the Tiger seal. Sasuke's right eye allows him to control the shape of the black flames through Inferno Style: Kagutsuchi, which turns Amaterasu not only into an attack tool but also into a defensive barrier surrounding the user.
