Sai is a type of weapon known in Japan, China, but especially popular in Okinawa. Unlike traditional wooden objects (tonfa, nuntyaku), the origin of which is associated with peasant labor, this weapon is very special. Sai is a type of long all-metal dagger with a guard of a special shape, which has several modifications. Usually these exercises are divided into basic technique, simplest combinations and kata. Naturally, they show style features, and the Kyokushinkai school is no exception. This concerns the implementation of the technique in the racks characteristic of the Kyokushinkai style, both on the spot and in movements, as well as the implementation of individual Kyokushinkai kata with sayas.