You might be able to trace your birth father if you have info on him because there are lots of internet sites that give servicemen info. As to your birth mom , any paperwork on her would be a big help. Knowing what town she lived in or how to spell her name with Kanji would also help. Any details you can find , the more the better. With little to no info , it is like trying to find a woman in the US with the last name of Smith who remarried and changed her name , very difficult. Good luck.