The Sai is a defensive truncheon originating in Okinawa. It is often mistaken for a dagger, as its use in the TMNT media would reflect. Several characters in the series have used sai, but they are mostly associated with Raphael.
In traditional sai combat, they are carried in pairs, called saitachi. One is used for blocks and trapping weapons, while the other is used for striking, mostly with the knuckle.
- In the 2012 TV series, Raphael's sai are the only weapon out of the four Turtles that is not designed to be a bladed weapon, unlike Leo's katanas, Mikey's kusarigama, and Donnie's naginata.
- In the 2007 film, during the fight scene between Raphael and Leonardo, Raph managed to break Leo's katana blades with his sai.