It seems that the setup in Japan is different.
In the USA, if you gave them $1,000, then the money was owned by FTX, but they owed you $1,000. Since they are bankrupt, they won't pay the $1,000 or only part of it. In Japan, if you gave them 100,000 Yen, it's your money and it stays your money, even though FTX Japan holds it on your behalf, and since it is your money, you can take it back. About the same as me parking my car in your empty garage; it's my car, and if you go bankrupt, it's still my car and I can take it back.