Mugilogobius flavomaculatus Huang, Chen, Yung and Shao, 2016 (Gobiiformes: Gobiidae) previously known only from Taiwan was newly recorded from Japan, based on a single specimen (30.9 mm standard length) from Iriomote-jima Island (24˚22'N, 123˚53'E), Yaeyama Islands, Okinawa Prefecture. The species is characterized by the following combination of characters: body with eight distinct black and seven yellow bands; cheek and operculum with dark net-like marking, surrounding five rounded pale blotches; caudal-fin base with a vertical black bar; first dorsal fin with a somewhat horizontal broad black band, rounded contour and non-filamentous spines; second dorsal- and anal-fin rays I, 8; and predorsal scales 19. Although M. flavomaculatus is similar to two presently unidentified Japanese congeners, Mugilogobius sp. 2 (Japanese name: Tanukihaze) and Mugilogobius sp. 3 (Mujina-haze), all three being assigned to the M. mertoni complex, the former is readily distinguished from the latter two species by the black and yellow bands on the body (body with X-shaped dusky markings in the latter), and (usually) I, 8 second dorsal- and anal-fin rays (usually I, 7). The new standard Japanese name Torahaze is proposed for the species.