Yosuke Igarashi , Ph. D. (Tokyo University of Foreign Studies, 2005) is a professor at NINJAL specializing in Japonic phonetics, prosody, and historical linguistics, with publications in Lingua, JASA, Cognition, and other journals. Celik Kenan , Ph.D. (Kyoto University, 2020), is a project assistant professor at NINJAL. He has published on Southern Ryukyuan prosody and co-edited a dictionary of the Tarama variety of Southern Ryukyuan Miyako (NINJAL, 2020). Tatsuya Hirako , Ph.

D. (Kyoto University, 2015), is an associate professor at Nanzan University. He studies Japanese dialects from descriptive and historical perspectives and has published a chapter in a volume from Brill's Endangered and Lesser-Studied Languages and Dialects series. Hayato Aoi , Ph.D. (Tokyo University of Foreign Studies, 2016), is a project assistant professor at TUFS. His research focuses on Ryukyuan phonetics and phonology, with recent interests in the history of Japanese phonetic and phonological studies.