It is short for sōson (惣村・そうそん) and seems to be a form of leadership for equality (solidarity). Also called an Ikki (惣村 一揆); manors (shoen, 荘園 or 庄園) still exist.
中世日本における百姓の自治的・地縁的結合による共同組織（村落形態）を指す。 Soson seems to indicate that its a self-government/territorial bond of unified peasants. Collaborative village. There are meetings to make collective decisions. It might have been formed like a ikki, with samurai and non-noble classes alike, to rebel against the Oda.
- (沙汰人) Term used to describe a person in charge of enforcement. They maintain security and taxation, and encourage agriculture (勧農).
The Mochizuki Family has founded Koga-Ryu and is one of the popular Koga families of Omi Province. While the Koga serve the Rokkaku Family, they want to preserve some autonomy in Koga.