This book provides a clear account of the temporal organization of Japanese phonology, especially the phonetic and phonological nature of moras, feet, and geminate consonants in Japanese. The topics covered include pre-nasal shortening, Japanese perception of rhymes, the occurrence of geminate consonants in Japanese compounds and English loanwords, sequential voicing called rendaku, and the bilabialization of /h/ in counting words which are preceded by the numerals san (three) and yon (four). The underlying theme is to provide empirical evidence of whether or not the mora controls isochrony in Japanese rhythm by analyzing the results of more than 20 production and perception experiments which were conducted with a total of 960 native Japanese and English speakers. This book is suitable not only for professional linguists, but also for people who are learning Japanese as a foreign language and wish to explore various theoretical issues of Japanese phonology.