Yes you can import cars from Japan urself and the most reliable auction house is USS, but there are some points you should consider.
1-In order to ship your car you need a container and a container usually contains 4 sedan size vehicles or 5 small like alto, vitz, passo etc. with whom you will share a container if you are not buying enough number to fill the container up.
2- Do you have any1 in Japan who can make payment on your behalf.
3- You should have some1 in mind who will help you in clearing process which includes the selection of Consignee. ppl usually buy the pasports which is not the safe way you should atleast know the consignee.