The Chidori was Kakashi Hatake's first original technique, though he later imployed the use of the S-ranked version of this jutsu known as the Lightning Cutter. He created it around the time he was promoted to jōnin, and later taught it to Sasuke Uchiha. Ryoji later learned it from an elderly Kakashi, who taught him the basic principles behind this unique jutsu and from then on created several variations of his own.