If your wife, her family, and Japan are all in unjust opposition to you and your rights as a husband and parent, perhaps it would be in your best interest to come back to the U.S.
If your wife has abandoned you without just cause, refused to communicate with you directly, is telling lies about you, and has stated that she wants you out of her life forever, then your obligation to her is finished. She is the cause of all your pain. You are not the one who is at fault.
You should come back to America where people care about you and will treat you with the respect and dignity you deserve. I have tried to make sense of the Japanese mentality for many years, and still cannot understand the way they view the world. It is completely unlike any other culture, and much of it I find highly offensive. You are not the one at fault. If no-one will help you, or reason with you, or compromise, then you need to leave.
I am truly sorry for all you have suffered.