chapotraphouse

Iirc at some point in Sengoku era they controlled entire Kaga province for years, but fell later as daimyos consolidated the power.

There was also armed buddhists temples, like Mount Hiei or temple at Osaka had few thousands armed monks at some points, and they were better armed than all feudal armies since some temples in Japan were for some reason arm producing centers and that included firearms. Unfortunately the usual organised and armed religion thing ticked off for them and unlike most ikko-ikki they were scourge of nearby territories, once even almost completely torched Kyoto in probably biggest and most violent monachomachia in history of mankind. Wiping them out was really best thing Nobunaga did.