Go here:
[Only registered and activated users can see links. Click Here To Register...] .
That will clean your inventory, even the binding items. Put in the storage all you need before doing this, and also put the equips you're wearing, because I don't know if it deletes them also.
Choose your character, put the code and click the button. If this message appears : "包裹清空成功!!!" then it went all fine. It other message appears then it's because the code is wrong.
I hope I've helped you ^^ .