I can't see the protoconch well in the pics, but all the other shell characteristics make this appear to be a Turbonilla or Amamimorula species (family Pyramidellidae, subfamily Turbonillinae). I searched for internet photos of about 10 different species that are similar, but without finding any of them. The written description or Amamimorula belonis, as well as the photo, in "Marine Mollusks in Japan" (Okutani), match your shell very well, but the singular photo I could find on the net looks significantly different. It might be an aberrant specimen, or it might be a different species (or my book could be wrong). The live-animal photos I have of Turbonilla species show the same dent in the anterior part of the foot, but some of the other animal characteristics are different. My guess is that it belongs to one of the two genera mentioned above, but could actually be one of several similar species. This family is often neglected in the popular literature, but that's not very surprising, since the same goes for most families with shells that are mostly very small.
The vast majority of rissoids (at least all that I've ever seen or read about) aren't nearly as elongate as the shell in the pics above.
Cheers,
Don