(meaning unclear; perhaps meaningless)
What does Hibiya mean?
Today’s place name is an interesting one.
The name 日比谷 Hibiya is 当て字 ateji. Ateji are words that use kanji characters for their phonetic properties instead of their ideographic properties. That is to say, the meaning of the character isn’t as important as the sounds. The meaning of the characters may be completely irrelevant or may have some forced meaning. For example, 珈琲 kōhī (coffee) is ateji. The first character refers to a kind of ancient hair pin. The second character refers to a string of pearls. The meaning of the characters is irrelevant and they are used to represent the sounds コー kō and ヒー hī (the latter is not even an sound native to the Japanese language).
As mentioned in the post about Chiyoda, before the Edo Period, Edo was just one of many small villages around what is now Tokyo Bay. Well before the Edo Period, the areas from Chiyoda (the Imperial Palace) to the sea were a mix of sea food production sites and agricultural areas. We can’t know for certain where it was, but one of the spots was on an inlet and was marked by 篊 hibi. Hibi are bunches of bamboo or brushwood used to grow and farm 海苔 nori (nori, a kind of seaweed).
The area was known for people and shops farming and selling nori (which was grown on hibi). Those people and shops would have been referred to as 篊屋 hibi-ya (hibi-people/hibi-shops). As the area grew (and the nori farmers presumably moved out), the place name came to be written 比々谷 Hibiya which has no meaning (ateji). The first character means “comparison” and represents the sound ひ hi. The second character just means “repeat the previous sound.” (the second “hi” become “bi” according to euphonic rules called 連濁). The final character is common in Japanese place names and means “valley.” This final character is also meaningless because there is no valley here. If anything, it’s part of the alluvial plain created by the waters in Tokyo Bay*.
Sometime in the Edo Period, 比々谷 came to be written as 日比谷 and that is the way it is still written today. The characters as they are now are “sun” “compare” and “valley, respectively.
If you go to Hibiya Park today, you’ll notice that there is a large pond near the Imperial Palace (Edo Castle). This pond was part of the system of moats around Edo Castle. The moat is gone today, but the pond is in its place. If you walk around the pond, you’ll notice a line of stone wall fortifications which match the castle area. This was one of the moat’s walls. Also, you’ll notice a photo spot called日比谷見附 Hibiya-Mitsuke (The Hibiya Approach). This was the path to the 日比谷御門 Hibiya Go-Mon, one of many gates into the castle. Btw, 見附 means “approach” or “walkway.” So Akasaka-Mitsuke meant “the Akasaka Approach.” More about that later.
The area that is the park today used to house 2 daimyōs’ upper residences; Saga domain and Chōshū domain.
* I’m not too familiar with geological terminology, but I think alluvium is the right word here. If I’m wrong, let me know and I’ll update the text.