If you are interested in linguistics...
Japanese onomatopoeia, mimetic words such as "kururi", "guru-guru" used for expressing body movement or emotional states, explain lots of the language and peoples' bodymind in Japan.

"kurui" means a body-turning once lightly, "guru-guru" a heavy and slow body-turning several times. There are 4500 or more such onomatopoeias used in the Japanese daily conversation. Japanese onomatopoeia is a highly systematized sound-symbolism using 50 Japanese "katakana" alphabets.
1)Kanji, 2) two sets of Japanese alphabet, 3)enigmatic onomatopoeia expressions, are the source of Japanese as "the devil's language".