Until I build up a callus I use white athletic tape. You can cut a piece the is just 1/4" square and it lasts a few sessions depending on how far. It does reduce the "feel" of the needle coming through but will help until you get the finger hardened up.
If you want, you can PM me and I am willing to send you some of the "dots" that I have seen in the store but not tried them.
Not sure that you can get Japanese website to mail to an APO address.