Gekisai Dai Ichi

In the "open hand" kata, there are two initial forms referred to as Gekisai Ichi (or Gekisai Daiichi) and Gekisai Ni (or Gekisai Daini) which are in practice very similar. Ichi and Ni mean 1 and 2 respectively, while "dai" means #. The "Dai" is sometimes dropped in the nomenclature.

Gekisai (撃砕) means "attack and destroy." These kata were created around 1940 by Chojun Miyagi and Nagamine Shoshin as beginner kata, to introduce the basic forms of karate (kihon) to middle school students in Okinawa, and to help bring about the standardization of karate, as well as to teach a basic set of techniques for self-defense. 

It is said that the two Gekisai kata were strongly influenced by the Shuri-te techniques that Chojun Miyagi learned from Anko Itosu, considered by many to be the father of modern karate.