My brother sent this to me. In 1942, the US War Department designed this comic book as part of a pocket book distributed to GI's fighting in the Asian theater. I remember seeing more of this kind of advice at a museum in Singapore claiming that the Japanese were generally cowardly and couldn't see at night (wrong on both counts and updated in this comic).
I've read that negativity directed towards the Japanese, especially in comparison to Chinese, predated the war and that Roosevelt also had a strong dislike for the former. This probably had a lot to do with the Soong's and their connection to the Roosevelts, the Methodist Church and various US publications including Reader's Digest and Time (which name Chiang Kai-shek and Soong May-ling man and woman of the year). In 1943, Soong May-ling became the second woman and first Chinese person to address the US Congress. Her little brother, T.V. Soong, is reported to have been a regular guest at the White House, where he played poker with the president.
It goes without saying that Japan threatened US interests in the Asian Pacific region a lot more than China.
A lot is made of the bushido code of the samurai: "Rippa ni shinde kudasai" or "Please die beautifully!" or "Don't let those barbarians get their smelly paws on you!" is what Japanese families might have told their relatives going off to fight. Still there were lots of Japanese in POW camps in New Zealand, Australia, the US and Canada.