[I am reposting this slightly modified article, which I inadvertently deleted a few weeks ago.]
The image on the left is a picture of the famous gold seal of the Japanese King of Na that was given by a Chinese Han emperor in 57 A.D. It is the oldest record of kanji writing that is related to Japan. The image on the right is an impression on wax. It reads, from the right to the left, Kan no Wa no Na no kokuoo 漢の委の奴の国王 “(Seal of) Japanese King of Na given by Han Emperor.”
The red image on the left is an impression of a rubber stamp of the replica. It is easier for us to see the writing. I would like to draw your attention to ancient writing in the center of the bottom row. Its kanji form is 奴. The left side (女) is a woman sitting with her hands crossed in front. The right side (又) is another radical shape called yoo or mata, and it pertains to a hand or an act that one does using a hand.
Look closely at the area marked in a blue box on the imprint of the seal in red. By contrast to the two ancient writings on the right, which showed three fingers, do you see an extra line in the seal? It is another finger! The seal maker must have reverted to the original meaning of a hand with fingers. It was a delightful discovery when I obtained the replicas from the Fukuoka City Museum.
Later on the kanji 奴 developed two different phonetic letters in Japanese: The right side 又 became a katakana nu ヌ; and the cursive style writing of the kanji 奴 eventually became a hiragana nu ぬ.[February 2, 2014]