Shell medium sized, attaining 31.2 mm; broad, fusi¬form shell with eight or nine nearly cylindrical teleococh whorls and straight spire outline. Protoconch unknown because of errosion. Distinct suture with broad subsutural ramp resulting in a stepped appearance. Penultimate and last adult whorl with 20-25 strong axial ribs, vanishing in the lower part of shell base. Fine spiral cords on top of the ribs, not bisecting the ribs, becoming stronger on shell base. Columella with four strong folds. Short, wide, nearly straight to slightly curved siphonal canal, aperture wide. Shell colour yellowish with one white central band on the spire whorls and three white bands on the last adult whorl.

The validity of Tosapusia kurodai has been repeatedly in doubt. Cernohorsky (1970), Hasegawa & Saito (1995), and Higo, Callomon & Goto (1999) synonymized it with Vexillum sculptile (Reeve, 1845), and Tsuchiya (2000: 561; pl. 279, fig. 31) treated it as a synonym of Vexillum rubellum (A. Adams & Reeve, 1850). We examined the two syntypes of Mitra rubella in NHMUK. The smaller one, apparently a juvenile, indeed shows an extreme resemblance to the holotype of Tosapusia kurodai; the only difference is a distinct notch at the tip of the siphonal canal, which is present in both syntypes of Vexillum rubella, but is absent in our specimens of Tosapusia kurodai. With its higher spire and slightly undulating ribs on the last adult whorl, the larger syntype of Vexillum rubella is nearly identical to specimens of Vexillum scitulum. In our analysis the latter was placed in Vexillum and we therefore allocate Vexillum rubella to Vexillum s.s. as well. We believe that Vexillum sculptile is also a Vexillum s.s. The examined syntype of Vexillum sculptile has a notched siphonal canal, distinctly arcuate axial ribs on spire whorls and undulating ribs on last adult whorl; these character states are shared by many Vexillum spcies, but not by Tosapusia kurodai or other Tosapusia species. We thus treat Tosapusia kurodai as a valid species of Tosapusia.
Tosapusia kurodai differs from most species of Tosapusia in shell proportions: it is characterized by a broadly fusiform shell with rather tall last adult whorl and low spire. Tosapusia vitiaz resembles Tosapusia kurodai in both shell proportions and sculpture pattern; however, Tosapusia kurodai differs from Tosapusia vitiaz by its much stronger and less numerous axial ribs and rather adpressed whorl profile (Tosapusia vitiaz is characterized by gently rounded whorls).

Southern Japan, the Philippines, Papua New Guinea, New Caledonia, depth range 356-600 m.