I was stationed at Camp Fuchinobe 1965-69. We lived in Minami-Rinkan, midway between NAS Atsugi and Camp Zama. It was pretty peaceful then. Most issues arose from brawling GIs up in the Tokyo area on R&R from Vietnam. Both bases were pretty open.
FEN would come on and warn Americans and dependents of “troubles” off base. Condition orange, then condition red meant stay on base or inside when the riots happened on May Day.