There are many writing systems currently in use around the world. For almost all of them, the basic mechanism is using graphical symbols to represent the sounds of language. A few dozen symbols are enough for this purpose. Japanese writing, however, includes Chinese characters (kanji), which are related not only to sound but also to meaning; since there are many possible meanings, kanji number in the thousands. The complexity of Japanese writing makes it comparatively harder to learn, and harder to process mentally. Why, then, is it still in use? Are there any advantages to such a system? A closer look show that Japanese writing allows modes of expression which would be impossible in a phonetic transcription of speech, or in simpler writing systems. This is an important datum, not only for Japanese studies, but for the linguistic study of writing itself; the Japanese case clearly shows that writing can't be adequately described as merely a visual representation of speech, but must rather be analyzed as an independent system for accessing language. In this dissertation we discuss, from Japanese examples, some of these expressive techniques which can only be realized in a written medium.