Students of Japanese may eventually begin to realize that Japanese, despite its wonderful array of phrases (particularly onomatopoeic), seems to be lacking in vocabularic variety. In a way, this a godsend: according to the Global Language Monitor as of October 2009, English has 998,773 words; compared with this, Japanese holds a measly 232,000. However, in another sense, as your skill blossoms towards fluency, you might begin to lament that often when you try to use a dictionary or thesaurus to variegate your Japanese, a native speaker will correct the word, replacing it with one that you already knew well.
This is partially because students have a poor grasp of which words to use when, but that isn't the whole story. Understanding dawned on me when I read the following post by a Japanese woman:
"An article said that English doesn't like to repeat the same word, so people use different words to write about things each time they appear in the same article. For example, when you write about an actress, first, you write about her by her name, after that, you should write about her using different words like these: she, the beautiful actress, the star and so on. Is it true?"
I realized then that the main issue was simply that Japanese people don't use a wide variety of words in comparison with English-speakers. But it would be a mistake to take this to mean that Japanese is limited, description-wise. English-speakers focus on adjectives to a far greater extent than the Japanese do. The Japanese tend to use nouns combined in unique ways more than unique words, like, "the moon shone like a blade frozen in blue ice." (Snow Country.) These are all really common words but their combination is singularly unique.
Even though Japanese has far fewer words, it has equal capacity for literary art; you simply have to alter your perspective a bit to achieve it.