As you seen in this photo, this produce not only use kanji, but also the katakana!!! Usually, katakana is used while people needs to transcribe the foreign loan words or it is used to emphasize the meanings, then it would use katakana instead of hiragana. Although both of them are syllabaries.
You may ask why the producer put Japanese on the produce which is selling in Hong Kong. It is because it raise the image of the produse since Japanese cosmestic produces are famous in the world. After adding those words, customers may feel more confident about the quality of it, more willing to it instead of others brand names.
