What is the author's style in The Samurai's Garden by Gail Tsukiyama?

The book is written in modern English, though there are several Japanese words scattered throughout the text. The majority of these are defined, though there are some that are considered common knowledge. The use of the Japanese is limited sufficiently so that the reader should have no difficulty keeping track of the meanings. The wording is typically casual, though the proper mannerisms and speech of the Japanese of the day is apparent in the dialog. There is also a certain formality in the way people react to each other, though it's more a described formality than a formality of speech.