Why is watermelon written in hiragana, whereas melon is written in katakana? For the two words, _watermelon_ and _melon_ : * watermelon → * melon → _Watermelon_ uses hiragana, whereas _melon_ uses katakana. Why is this set up this way? Is there a special rule that dictates the use of katakana in the original word or something?

is a Japanese word, borrowed from the Chinese. It is not known exactly when watermelons arrived in Japan, though it was most likely after the Muromachi period (1333-1573 CE). Words which are native to Japan, borrowed from China, or borrowed a long time ago tend to be written in Kanji and Hiragana. Incidentally, means _west_ and means _melon_ or _gourd_.

on the other hand is an imported word from the English _melon_. This word refers to Muskmelons which were imported in the late Meiji (1868-1912 CE) or early Taisho (1912-1926 CE) periods. Words which are not Japanese or Chinese in origin are often written in Katakana.

Normally, melons which were passed to the east of the Middle East contain the kanji and melons passed to west of the Middle East contain the word .