Yantsu is an old kata with unknown origin that is alternately classified as belonging to the Naha-te or Tomari-te karate tradition. Outside of kyokushin, it today is only practiced in Motobu-ha Shitō-ryū (that today is part of the Nihon Karate-do Kuniba-kai), where it in a slightly longer variant is called "Hansan" or "Ansan". The name Yantsu translates to "keep pure". How the kata was introduced into Kyokushin is unknown, although it is speculated that it was somehow imported from Motobu-ha Shito-ryu.