The Sankosha logo was an entwined KS inside a double circle that was broken in three places and had a cross bar in the intermediate three sections. The K was solid and the S was outline similar to the outside made by the two circles.

Sankosha regulator, 1900-ish. Sankosha was part of a government study in 1947 to develop a standard clock movement for the Japanese clock industry. This one is small... 21 3/8" tall, with a 6 3/4" chapter ring.