Tomoe

A tomoe or tomoye (archaic) (巴) is a Japanese abstract shape (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.

They appear in the Sharingan eyes, and they also form the Cursed Seal of Heaven which Orochimaru put on Sasuke Uchiha and Anko Mitarashi.