“the words in the two small circles don’t have any meaning, it's kind of mark.”
I would not say so. Near the right circle we find the red character 字 (zì), which means something like “block character”. In this case the block character is 阿 ( ā).
The block character changed at every 999 notes. That means there existed 999 notes with each block letter.
Outside the left circle we see two red characters, namely (from right to left) 第 …………… 號 (di……..hao) which means „number….“.
Between these two red characters we find 3 characters. These characters represent the serial number.
We can see –again from right to left– the characters for 4, 7, and … (the 3rd character is illegible to me). These digits are not written with the normal characters (四 and 七), but with more complicated characters, namely 肆 and 柒.
The genuine notes were printed in Japan, by 大日本帝國政府印刷局 = Printing Office of the Great Imperial Japan, as can be read at bottom of the note (below the house). Immediately after the notes were issued, counterfeits became known in big quantities. So a 2nd series was ordered, similar, but not the same: in the notes of the 1st series the coins touch the frame at right and left, in the 2nd series they don’t.
Erwin
