After 13 years, less bug 273 marked as fixed in (beta?) version 485, and
it seems everything works as of debian package version 487-0.1 (in
ja_JP.UTF-8 locale; in non-utf-8 locales - e.g. ja_JP.EUC-JP or
ja_JP.SJIS - it seems still broken, but debian consider them deprecated
anyway).