In 1948 Kimihiko Yasuma started making Guitars in Nagoya. In 1950 he founded K. K Yasuma Gakki and was making Guitars branded New Ance, (yes it was suppose to be a pun on nuance), and this appears to have appeared on the headstock, certainly of some Tiple Ukuleles along with the K Yasuma & Co. logo. Why it was used on some but not all I don't know maybe to keep the branding for Japanese sold instruments, maybe to move away from the Martinesque headstock logo? 

In 1960 the firm was incorporated and became K. Yasuma & Co., (for some reason I can't translate they may also have made instruments branded T Yasuma between 1953 and 1970?) It appears from the website that the firm still exists in some guise though I haven't seen any instrument by them in this millennium, (possibly because they make acoustic Guitars for Yamaha? they certainly have in the past). When they were making Instruments they made Guitars, Mandolins Ukuleles and Tiple Ukuleles that were very good copies of Martin Instruments. So good in fact that Martin won a court case for copyright infringement against them in the U.S. and had a lot of the Yasuma instruments in the US destroyed. (When people talk about "Lawsuit Guitar" this is the case they forget, Gibson only ever threatened court action, they never actually went to court, but the threat carried weight because of what Martin did to K Yasuma). This ruling did not affect their products outside of the U.S but they did change their headstock logo to look less like Martins after. The company did continue after the lawsuit making instrument that looked less like Martins but I don't know when the last Yasuma branded instruments were made?