Software to rename files with Japanese or Korean character/letter filenames to their Romanized (Roman/Latin letters) equivalents [closed]

ReNamer v6.5 comes with transliteration maps for Japanese language. Included maps adhere to Hepburn-shiki and Kunrei-shiki romanization systems.

Japanese transliteration map in ReNamer


Try the latest portable beta of ReNamer (an extremely powerful bulk renamer with in-built scripting support), then take a look at its Transliteration feature. The forum is pretty helpful as well and the developer is quite responsive to suggestions/requests, so if your language isn't supported out of the box maybe someone has shared their translit file in the forum or is willing to help.