Where the hell are you guys getting these? xD I spent most of Tues, all day yesterday, and all day today playing online and I haven't come across any bones with Japanese text(which people say are usually level 99) or any bones that are level 99. And I pick up every pile I see. Man, I must just be unlucky.
You have to join a lvl 99 players game and then pick up the bone within their game. Usually you will get a copy of the character what that lvl 99 player is using. I got 30 lvl 99 bones and im only lvl 35
Not specifically lvl 99. I think you happened to get the bones of someone who hacked his/her game. Can be any level. :( Just hope not to get the bad item when you bury their bones. Maybe have a full inventory when you try? I wonder if Atlus tech support can help.