When adding or editing a new release, and coming to the recording association step, searching for japanese titled songs with no latin characters returns no results. Japanese is the only language I've identified, because the same problem does not occur with purely Korean titles.
Adding even a single Latin Character causes results to occur, relevant ones at that. Japanese characters don't appear to be getting stripped out, but using nothing but them results in an error.
Since the search boxes are a little small and the screenshots don't show the entirety of the text, note that I searched first for "エブリデイ・ラブリデイ
L.E.D. Style Mix (feat. Sana)", then solely "エブリデイ・ラブリデイ".