Yamamoto Shashinki Kōsakusho
Yamamoto was a Japanese company making or selling cameras before World War II. They sold the Semi Kinka, a 4.5×6 folder, copy of the Nettar.
Maybe it was the same company as the distributor Yamamoto Shashinki-ten (山本写真機店, means Yamamoto Camera Shop) who sold the Weha Chrome Six from 1937, and a 6.5×9 folding plate camera called Weha Light around 1930.