Chidori

Chidori is Kakashi Hatake's only original technique, though he now uses an S-ranked version known as the Lightning Blade. He created it around the time he was promoted to Jonin, and later taught it to Sasuke. This jutsu channels a large amount of chakra into the user's arm. The amount of chakra is so great that it becomes visible to the naked eye. The technique actually alters the nature of the user's chakra, effectively converting it into electricity. As a side effect of the conversion process, the large amount of chakra, and the speed at which the user moves, this technique makes a loud noise similar to many birds chirping, hence the name (if the user is not in motion, it merely makes an electric crackling sound). Once the technique is completed, the user charges forward and stabs their enemy with it. The amount of thrust combined with the large concentration of chakra allows the user to stab through almost anything; as such it is usually fatal to the enemy. This technique is classified as an assassination technique because of the speed at which it is performed, despite the loud noise it produces.

This jutsu has a major drawback, however. The speed at which the attack must be done, combined with the fact that the user must run in a straight line, causes a tunnel vision-like effect for the user. This allows their enemy to easily counter the attack, making it a potentially lethal move for the user. Though this drawback would seem to make learning the technique fairly pointless, Sasuke, Kakashi, Indo, and Hayai are able to avoid the drawback because of their Sharingan eyes and Itakue fixes that problem by using his morigan, which take in every detail regardless of how fast the user is moving. As an additional drawback, the large amount of chakra required limits its use to a few times a day (two for Sasuke, four for Kakashi, six for Indo, four for Itakue, and three for Hayai). Sasuke can manage one more than normal with the use of his cursed seal. Should the user attempt to go beyond their limit, all of their chakra will be drained and their very life force could go along with it, killing them. An additional problem, though not necessarily a debilitating one, is the fact that the large amount of chakra can also injure the user's hand if they put too much force into the attack. Sasuke does this while battling his brother, Itachi Uchiha, causing some of the skin to peel from his hand and leaving it slightly smoldering after the attack was finished.

Naruto also wanted to learn it, but since he does not have a Lightning affinity and lacks the Sharingan eye, this was impossible. Instead, Jiraiya convinced him to go with him to find Tsunade by offering to teach him the Rasengan.

In Part II, Sasuke has mastered the principles of Lightning manipulation and developed a number of other Lightning Release jutsus, most of which are derived from the Chidori.

Seireitou also makes this jutsu his own, while using all of Sasuke and Kakashi's Variants, he makes a few of his own, some with diiferent Elements. Seireitou also later teaches this jutsu to Haizo which Haizo then makes it his own.

Indo tries to learn one thousand birds himself, but do to his inability to master jutsu regularly, he made a glitched purple one that he called, "Shadow Ball", and instead of piercing the opponent, it explodes when it touches.

Eight-Tails Influence
Riyan has shown that when he is under the influence of the Eight-Tailed Giant Ox's chakra, he can improve his use of the standard Chidori and simultaneously make up for his shortcomings in performing the jutsu. Due to the influence exhibited by the Eight-Tails' chakra, this Chidori changes from its blue color to a purple, orange, or red color, while also being stronger than its standard version. Despite the fact that this jutsu has its own name, Giant Ox Chidori (巨牛千鳥, Kyogyū Chidori), it is fundamentally the same jutsu.

Variants
Shadow Ball Chidori (created by The Slabia of Darkness)

Raikiri

Habetaku Chidori

Chidori Nagashi

Chidori Spear

Chidori Stream

Chidori Senbon

Chidorigatana

Chidori Raimei

Ion Lightning Rod

Kirin

Raijuu (idea based on)

Chisengan

Radori

Raikiri Current

Odama Raikiri

Chidori Nagashi: Hiraishin no Jutsu

Fire Release: Raikiri

Hazard

Ranryoku Raikiri

Chidori Taihou

Oni Chidori

Raikura