Japanese language has lots of borrowed words (loan words). These words mostly came form Chinese, English and French. When Japanese introduced a new word from foreign language, they tried to replicate the pronunciation of the word. Some textbooks said that the loan words were widely used in fashion magazine because they had an impression of modernity. (One other reason might be people are tired of keep creating new words for their language.)
The first word I found is ビタミン(vitamin). ビタミン is a loan word from English. I found this in a Japanese food magazine. I found there are lots of loan words in food magazines. This was reasonable because many food were introduced into Japan later.
The second one I found was ライスカレー（rice curry). This is also a loan word from English. I found this word on the menu of a Japanese restaurant.
The most interesting word I found is ピカチュウ. The person who named it said that this name is a portmanteau of the Japanese words pikapika(ピカピカ), an onomatopoeia for electric sparkling, and chū, which is the Japanese onomatopoeia for a mouse's squeak.
イージーレギンスパンシ(Easy leggings pants). I found this loan word two days ago on a price tag. Easy in hiragana is かんたんな. But on the price tag, they use katakana instead of hiragana. Maybe it tried to emphasize on the word.( Another reason might be they tried to reach a conformity because leggings pants was written in katakana??)
Different textbooks explained the use of katakana in different ways probably because these textbooks were written in different times. Language was not just about the language, it was also about the culture behind it. We sometimes found it hard to perfectly translate a foreign word into another cultural settings. Even if we could translate, the word lost some meaning associated with its original culture.
