Remember how people always laugh at the French because they outlawed the word “le hamburger,” and they don’t say ‘email address,’ they gotta say, ‘adresse de courrier electronique?’ When an English word gets popular, they stone cold invent a French version, rather than polluting their language with outside terms!
Well, back in the pre-WWII days, Japan did the same thing.
Today if they want to import a new word, like ‘customer support’ they’ll use katakana: カストマー・サッポト。 But back in the Pearl Harbor days, speaking the words of inferior mongrels was pretty gauche. What they’d do instead was, break the foreign compound word down into its basic parts, then find the kanji which corresponded to those parts, and combine those kanji to make a new Japanese word – a NEOLOGISM.
For instance, wheel-chair became 車椅子 （car-chair), and space-ship became 宇宙船 (universe vessel).
Of course, these ‘pure Japanese’ words were written in Chinese, but whatever. When have racists ever made sense?