Amaterasu


 * Name:
 * Type: Kekkei genkai, no rank, offensive
 * Users: Itachi Uchiha

Amaterasu is unique to the Uchiha clan. The jet-black flames are said to be as hot as the sun, and will burn for seven days and seven nights. Since the Mangekyo Sharingan is necessary to activate this jutsu, not many have learned it. All that is known is that it is very powerful since it can punch through a Mountain Toad's stomach which is, as stated by Jiraiya, fire retardant. Not surprisingly, it appears to use a large amount of chakra. Though stated in the databook to burn everything reflected on its retina; Zetsu also commented that the Amaterasu burns everything within Itachi's field of vision to cinders with an unholy black flame. Also of note, like Kakashi's Mangekyo technique, Amaterasu apparently requires hand seals though this can be circumvented with more time.

After Sasuke escaped Tsukuyomi all Genjutsu use in the battle between the brothers became pointless. Itachi was forced to shift from the most powerful illusion to the most powerful real attack. As opposed to Tsukuyomi which originates in Itachi's left eye, the Amaterasu comes from his right eye. Apparently only one eye is required for Mangekyo Sharingan Dojutsu in this case the right. Although not shown in it's entirety when used while escaping Jiraiya in the battle with Sasuke either through fatigue or deterioration of his Sharingan, but Itachi's eye was strained to the point that his drew tears of blood while executing the Amaterasu.

Influences
As from the ancient Japanese myth of Amaterasu and Tsukuyomi where when Izanagi washed his face after escaping the underworld his left eye became the Sun Goddess Amaterasu.