hat is named just fine as long as inside that folder you have
PS3_GAME
PS3_UPDATE
PS3_DISC.SFB
Check that rename the Folder BLJS10258/PS3_GAME- to BLJS10258/PS3_GAME ! or the game won't work.
That could be your problem. Check inside that folder.
Read more: http://www.ps3news.com/forums/ps3-help-support/ps3-japanese-game-error-help-129795.html#ixzz38Hw7TIrh