---Tsukuyomi---

According to Zetsu, Tsukuyomi is one of the most powerful genjutsu in existence. It is unique to the Uchiha clan and only those with the Mangekyo Sharingan can perform it. It is said to represent the "Spiritual World and Darkness" (精神界と闇, Seishinkai to Yami), the antipode to Amaterasu, a ninjutsu of similar power. Tsukuyomi requires eye contact to be performed. When executed, the technique traps the target in an illusion that is completely controlled by the user. Itachi's prowess with the technique has allowed him to alter the perception of time with ease within the genjutsu to make it seem to last for days when in fact it only lasts a few seconds. This allows him to torture the target for what seems like days on end, causing mental trauma that will render them unable to fight for an extensive period of time. After Itachi used it on Kakashi in Part I, Kisame was surprised that Kakashi was still alive. Only Tsunade has been shown capable of curing this psychological damage.

In the anime during Part I, Itachi's use of Tsukuyomi typically featured a red moon casting a red light throughout the illusion with a cloudy atmosphere, giving the background a blood-red appearance while the victim within the illusion is in depicted in an inverted grey scale.

Such a powerful technique is not without its disadvantages, however. Due to the complexity of the illusion and the quickness with which it is executed, an enormous amount of chakra is necessary and an added amount of stress is placed on the left eye, leaving Itachi's vision to be more darkened. Before using it on Kakashi in Part I, Itachi stated that Tsukuyomi can only be broken by a Sharingan user that shares the same blood as him; as demonstrated when Sasuke overcame Itachi's Tsukuyomi in their battle. Sasuke can also perform Tsukuyomi with his right eye, though his illusion is considered inferior to Itachi's Tsukuyomi since it does not alter the opponent's perception of time indicating he has yet to master it.

Tobi's Eye of the Moon Plan involves acquiring the Ten-Tails' power and body in the moon, which allows him to cast an "Infinite Tsukuyomi" (無限月読, Mugen Tsukuyomi) throughout the entire world, effectively letting him conquer it. However, while it is unknown if Tobi is capable of using the normal Tsukuyomi, Madara Uchiha most likely can as a user needs to awakened both Tsukuyomi and Amaterasu in order to use Susanoo.

---Mythology---

The second of Izanagi and Izanami's "three noble children," and usually considered a male kami with rule over the night. The name tsuku-yomi is thought to be originally related to the lunar calendar, and refers to the "reading" (yomu) of the phases of the "moon" (tsuki). According to Kojiki and an "alternate writing" in Nihongi, Tsukuyomi came into being when Izanagi washed his right eye as he was undergoing ablution. Tsukuyomi was entrusted by Izanagi with rule variously over the sea (Nihongi) or over the realm of night (Kojiki). In the main account of Nihongi, Tsukuyomi is produced jointly from Izanagi and Izanami, and is entrusted to the sky as a complement to the sun kami. In another "alternate writing" related by Nihongi, Tsukuyomi comes into being from the white copper mirror held in Izanagi's right hand. These accounts of the kami's genesis, involving the juxtaposition of left eye to right eye, left hand to right hand, and sun to moon, tend to agree with the interpretation of Tsukuyomi as a male counterpart to Amaterasu, who is commonly considered female.

In Kojiki, Tsukuyomi does not appear again after the anecdote regarding his birth, but an "alternate writing" in Nihongi relates that Tsukuyomi originally resided together with Amaterasu in heaven, but after killing the kami of foods Ukemochi, he was condemned by Amaterasu as an "evil kami" and forced to live apart from the sun, resulting in the separation of day and night.

Nihongi's record of Emperor Kenso includes an episode in which a human medium delivers an oracle of the moon kami stating that land should be offered to the kami Takamimusuhi. The fact that the aforementioned "alternate writing" transmitted by Nihongi describes Tsukuyomi as ruler of the sea and killer of the food deity Ukemochi gives him characteristics in common with the kami Susanoo; in consideration of the theme of the killing of the food deity and the relation of the moon to harvest in the lunar calendar, Tsukuyomi can be considered a tutelary of agriculture.

Tsukuyomi is the object of worship (saijin) at the detached shrine (betsuguu) Tsukuyomi no Miya of the Grand Shrines of Ise (Ise Jinguu), as well as at several shrines listed in the Engishiki in the Yamashiro and Ise areas.

Name : Uchiha Tsukuyomi

Title : Chitsuki no Tsukuyomi

Nickname : Tsu or Tsuki

Age : Twenty Nine

Family : None

Children : None

Religion : Jashinism (non-Hidan-like)

Elements : Fuuton and Suiton

Major Stat : Speed

Occupation(s) : Monk, Librarian, Salesman, Samurai