This is the mark of the Bank of Japan.
It's printed on the back of the banknote.
In one corner of Sakamoto Park, there is "Kabuto-cho / Kayabacho Machikado Exhibition Hall". It is on display along with portable shrine, floats and fire-related materials.
The mark can be read as "day" and "books" in kanji can be read as Japan in a half coat made of deer skin. It is said that it was given by the Bank of Japan during the Taisho era. It's a very innovative design.
Why don't you take a look while shopping in Nihonbashi?
You can see it. 。 。 。
Do you want 
to get more money?
