From AikiWiki - AikiWeb Aikido Information

[edit] Gozo Shioda

One of O-Sensei's earliest students was Gozo Shioda Sensei (1915 - 1994). Although Shioda Sensei thrived in the hard training, he found the manner of teaching within O-Sensei's dojo difficult, as there was little tuition, only "stealing with the eyes", so he would watch Ueshiba Sensei's body movements, every muscle, the way he kept his feet under his body, and analyse the technique to it's integral parts. Shioda Sensei then devised a system for himself to learn Aikido, and later to help others teach. This system became the Yoshinkan teaching system.

Shioda Sensei was concerned with the idea of the straight center-line and keeping this line when moving. He was so incredibly quick and his Aikido so powerful because he could maintain his center-line throughout his techniques.

Shioda Sensei formed the Yoshinkai with the backing of Japanese financiers and the support of O-Sensei. Yoshinkan Aikido became famous for its form and "hard" technique.