During three cruises of TRV Toyoshiomaru, 4 families, 16 genera, and 36 species of Myodocopida (Ostracoda) were collected from the southern part of the Sea of Japan, Ariake Sea, and Seto Inland Sea. Because most (27/36) species are undescribed, current taxonomic studies are insufficient for these myodocopids. This paper supplies an illustrated guide to the genera of Myodocopida obtained on these cruises. This contribution is expected to lead to improved taxonomic knowledge of Myodocopida.