A Study of Tone-Marked Manuscripts of the Kokin Wakashu is Kazue Akinaga's extensive scholarly work built on years of research into classical Japanese. Using tone-marked manuscripts as evidence, it examines the text, annotations, and phonological history of the Kokin Wakashu in detail.

From small tone marks, the work uncovers the history of reading and sound in classical waka.

The Hittite Mediopassive Endings in -ri is Kazuhiko Yoshida's specialist study of Hittite verbal morphology. It examines the distribution and development of the mediopassive ending -ri within Indo-European comparative linguistics.

Through Hittite verbal endings, the book reconsiders the verbal system of Proto-Indo-European.