Kanbun Uechi was supposed to have studied martial arts with an instructor in Fujian, China known as Shushiwa. Whether this was his real name, a translation, or a knickname cannot be positively determined as far as I can tell. He was believed to be an instructor of Fujian Tiger fist. While in China, Uechi learned three forms- Sanchin, Seisan, and Sanseiru. I remember reading somewhere that he was unable to learn the fourth form, Suparinpei. All four of these forms exist in Goju-ryu, but in a different form. The Uechi version of Sanchin, for example, uses open hands as opposed to Goju's fists, and has a different breathing pattern. Supposedly Kanbun Uechi called what he had learned "Pangainoon", claiming it meant half-hard, half-soft. Later, practitioners began to refer to the style as "Uechi-ryu". As punisher73 stated above, a splinter group (or groups) started once again referring to it as "Pangainoon", perhaps due to some conflict with the Uechi family.