Japan has undergone a national linguist phenomenon between 2006 and 2007. It was called Lou Go, which means ‘Lou Language’ in Japanese. Lou Go became popular among Japanese teenagers and young adults, which lasted for approximately one year. Lou Go’s characteristics are analysed through several Lou Go texts and Katakana texts both quantitatively and qualitatively. Although both Lou Go and Katakana texts share similarities in the sentence structure and the use of borrowing words, there were differences in the language switching in word class level. It also uncovered that a number of borrowing words do not affect the readers’ understanding of the Katakana texts as long as the borrowing words are nouns and pronouns. The success of the Lou Go phenomenon may be summarised by two factors. The first is ‘bilingual experience’ among the Japanese and the second factor is the influence of globalisation and the Japanese educational policy.