Kanji creates words and makes the Japanese language logical. This is part of the fun of it all. But sometimes logic is pushed over for the harmony of sound. Which is fine, but makes those smooth links more rigid.
One of the best examples is 銀行 (ぎんこう) or bank. This word has been around since 1872 when the national bank was formed. Since the concept of a bank was new, they needed a new word. Borrowing from foreign words wouldn’t become in style for many years to come, so バンク wasn’t available (though it is used now in a number of circumstances).
So they decided to take the Chinese kanji 行, which means store or shop (the Japanese equivalent is 店), and needed to add the kanji for money before it. Since the bank would handle 銀 (ぎん silver) and 金 (きん gold), they had two options. 金 seemed like the obvious choice.
But it didn’t make the cut. Why?
Because it’s 語呂 (ごろ – sound harmony) wasn’t up to par. ぎんこう sounded better than きんこう.
This is the way a lot of Japanese has developed. What’s fascinating about this is that without knowing the language, this sound harmony is out of reach. But the more you dive into Japanese, the more you start to feel the 語呂. Feel the Goro!
The next time you wonder why a word isn’t the way you’d imagine it should be, you can blame the bank. Or samurai bank robberies (I really hope this was a thing).