Unsu (Hands in the Clouds) is a high level kata and one of the oldest practiced within Shotokan karate. Its exact origins are unknown but it is believed to be of Chinese origins, and of the Dragon Style of Kung Fu. According to Masatoshi Nakayama, (seen performing Unsu above), anyone who tries to master Unsu before first mastering the Heian kata, Kanku-Dai, Empi and Jion will look like “a scarecrow trying to dance".

Symbolism is a recurring theme in the history of the martial arts and it has been suggested that the moves in Unsu represent a thunder storm. The first move could be said to be representing a squall line on the horizon, the way the feet draws circles on the ground along with the finger strikes in subsequent moves representing dust devils gathering as lightning strikes the ground.

Following this, the rapid movements in all directions can be seen as symbolic of winds blowing in all directions, and generally throughout the kata the slow movements can be seen as a calm in the storm before it blows up again ferociously. Finally, towards the end of Unsu, the jumping, spinning back kick can be seen as a tornado.

The son of sensei Gichin Funakoshi, Yoshitaka, was sent to learn kata from Okinawan master Kenzo Mabuni and as a result of these teachings, the curriculum of Shotokan is believed to have included Sochin, Nijushiho and Unsu.