What kind of abomination of a traffic sign has the form a yield sign but the text of a stop sign? Maybe this means Japan doesn't even have a yield sign if the stop sign is the inverted triangle that elsewhere in the world is for yield. So, stop exists but the one to yield is always the man/woman with a shorter katana.
Stop signs in Japan are solid red with a white border and the text 止まれ (which I assume means "stop") on them. In Okinawa they had "STOP" in English as well back when I was there, but Okinawa's signs are a bit special since it has so many Americans there.
Strictly speaking, Japan doesn't have a yield sign in the same sense that the US does. It has a "slow" sign that's a hollow red triangle with a white border and center. To get the same effect, you apparently combine a "slow" sign with a rectangular sign below it that says to yield to traffic. I don't remember ever seeing that in Okinawa, but it's been over two decades since I lived there.