Researchers interested in second language attrition have studied a wide variety of bilingual speakers, ranging from foreign language students who learned a language through classroom study to those who have developed high proficiency during life abroad. What these studies have in common is their investigation of questions related to bilingual speakers' loss of L2 knowledge or proficiency. Hansen's collection of papers presents research on a range of bilingual speakers who have the Japanese language in common, whether that language is their L1 or L2. The book is divided into two major sections. The first section, consisting of three papers, presents studies of Japanese children of elementary school age who learned English while living abroad but who have returned to Japan. This section will be of interest to EFL teachers of children as well as to L2 researchers. The four papers in the second section of the book examine the attrition of Japanese by adults. Most of these adults became subjects while residing in the United States after working or studying in Japan. The adults studied in these chapters had a variety of different combinations of exposure and formal study and also a broad range of years away from Japan, from 9 months to 30+ years. Additionally, the subjects of one study never lived in Japan at all but learned Japanese during Japan's occupation of Micronesia.