Tomoe

A is a Japanese abstract shape, usually used as a necklace, (i.e. a swirl) that resembles a comma or the usual form of magatama. Tomoe are usually seen in a design of three known as.

Canon Uses

 * They form the pattern of the Sharingan.
 * They form the Cursed Seal of Heaven.
 * They are on Madara Uchiha's gunbai.
 * The Three Giant Snakes have tomoe markings on their heads.
 * Orochimaru himself wore blue tomoe-shaped earrings.
 * The magatama earrings worn by Itachi's Susanoo are in the shape of tomoe.
 * The Yasaka Magatama technique used by Itachi and Madara's Susanoo is a giant shuriken in the shape of a mitsudomoe. After transplanting Itachi's eyes, Sasuke has used his Susanoo to fire tomoe-shaped projectiles made of Amaterasu's flames.
 * All the variations of Nine-Tails Chakra Mode shrouds feature tomoe-like markings around their collars.  Same goes for Tenseigan Chakra Mode.
 * The Sage of the Six Paths had tomoe-like markings around the collar of his cloak as well as nine tomoe of the back underneath the symbol of the Rinnegan; the same held true for both Obito and Madara Uchiha after they became the Ten-Tails' jinchūriki,  and for Naruto when he enters Six Paths Sage Mode.
 * A seal that the Sage of Six Paths stood in the middle of while talking to the nine tailed beasts also featured the use of tomoe markings.
 * The holes for eyes in Tobi's mask during the Fourth Shinobi World War are tomoe-shaped.
 * There are tomoe-shaped markings around the kanji for "fox" in the Uchiha Hideout.
 * They are on the third eye of Madara Uchiha and Kaguya Ōtsutsuki, as well as of the latter's incarnation.
 * They are used on the doorway of the Ridge Tower.
 * They are in Sasuke's Rinnegan.

Non-canon Uses

 * The Kohaku clan's insignia is a futatsudomoe (tomoe in a design of two).
 * The Shirogane clan's insignia is a golden mitsudomoe.
 * In the anime, later depictions of Pakura's Scorch Release: Extremely Steaming Murder changed the flaming orbs into flaming tomoe shapes.